Brian Carnell's Wiki

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
<html>
<div>
<h1 class='c000'>THE SNAKES OF EUROPE</h1>
</div>
<div class='pbb'></div>
<hr class='pb' />

<div class='nf-center-c0'>
<div class='nf-center c001'  >
    UNIFORM WITH THIS VOLUME
  </div>
</div>

<div class='nf-block-c0'>
  <div class='nf-block'>
    <p>
    THE LIFE OF CRUSTACEA<br />
    BRITISH FRESHWATER FISHES<br />
    THE OX AND ITS KINDRED<br />
    THE LIFE OF THE MOLLUSCA
    </p>
  </div>
</div>

<div class='pbb'></div>
<hr class='pb' />

<div class='nf-center-c0'>
  <div class='nf-center'>
    <span class='xlarge'><b>THE<br />
    SNAKES OF EUROPE</b></span><br />
    <br />
    <span class='smaller'>BY</span><br />
    <br />
    <span class='larger'>G. A. BOULENGER</span><br />
    <br />
    <span class='smaller'><span class='sc'>LL.D.</span>, <span class='sc'>D.Sc.</span>, <span class='sc'>Ph.D.</span>, <span class='sc'>F.R.S.</span>, <span class='sc'>F.Z.S.</span></span>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c001'  >
    <span class='smaller'>WITH FOURTEEN PLATES AND FORTY-TWO FIGURES IN THE TEXT</span>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c002'  >
    METHUEN &amp; CO. LTD.<br />
    36 ESSEX STREET W.C.<br />
    LONDON
  </div>
</div>

<div class='pbb'></div>
<hr class='pb' />

<div class='nf-center-c0'>
  <div class='nf-center'>
    <i>First Published in 1913</i>
  </div>
</div>

<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>
  <h2 id='preface' class='c003'>PREFACE</h2>
</div>
<p class='drop-capa c004'    >There is no work in the English language
dealing with the Reptiles of Europe. I have
therefore endeavoured to supply this desideratum, so
far as the Snakes are concerned, by drawing up in a
concise form an account of what is known of their
characters, their distribution, and their life-histories.
Professor Sordelli, of Milan, having kindly acceded
to my request to reproduce some of the beautiful
figures drawn by him for the work published in
collaboration with the late Professor Jan under the
title of “Iconographie Générale des Ophidiens,” I have
been able to supplement my descriptions with illustrations
which leave nothing to be desired from the
point of view of accuracy. A few drawings have
been made specially for this book by Mr. J. Green.
I have further to acknowledge the permission given
by the Trustees of the British Museum, the India
Office, and the Zoological Society, to reproduce a few
figures from previous publications of which I am the
author.</p>

<p class='c005'>In order to render this little book more useful, the
account of the Snakes of Europe has been preceded
by an Introduction summarizing what is known of
Snakes generally.</p>

<p class='c005'>I have purposely avoided overburdening a work of
this kind, which aims at concision, with bibliographical
references and synonymic lists. I am sure my
readers will be thankful for being spared this display
of erudition. Whenever I have had to compile, and
to trespass on ground that is not my own, I have
been careful to draw only from the writings of the
most trustworthy authorities. The descriptions of
the species are based on the collection in the British
Museum, which has been considerably increased
since the publication of the Catalogue of Snakes
(1893-1896). I have also had access to Monsieur F.
Lataste’s rich private collection, now under my care,
and Dr. R. Gestro has kindly entrusted to me for
study the collection of Italian Snakes in the Genoa
Museum. I am indebted to Dr. L. W. Sambon for
the chapter on Parasites, which he has written at
my request.</p>

<p class='c005'>To all who have helped me I beg to tender my
hearty thanks.</p>

<div class='nf-right-c0'>
  <div class='nf-right'>
    G. A. B.
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c002'  >
    CONTENTS
  </div>
</div>

<table class='c006' summary='Table of Contents'>
<tr><td class='c007' colspan='3'>INTRODUCTION</td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='smaller'>CHAPTER</span></td><td class='c010'><span class='smaller'>PAGE</span></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>I.</td><td class='c009'><span class='sc'>Definition and Classification</span></td><td class='c010'><a href='#Page_1'>1</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>II.</td><td class='c009'><span class='sc'>External Characters—Integument</span></td><td class='c010'><a href='#Page_8'>8</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>III.</td><td class='c009'><span class='sc'>Coloration</span></td><td class='c010'><a href='#Page_29'>29</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>IV.</td><td class='c009'><span class='sc'>Skeleton</span></td><td class='c010'><a href='#Page_40'>40</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>V.</td><td class='c009'><span class='sc'>Dentition</span></td><td class='c010'><a href='#Page_53'>53</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>VI.</td><td class='c009'><span class='sc'>Poison Apparatus—Different Kinds of Poisons</span></td><td class='c010'><a href='#Page_62'>62</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>VII.</td><td class='c009'><span class='sc'>Nervous System-Sense Organs</span></td><td class='c010'><a href='#Page_73'>73</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>VIII.</td><td class='c009'><span class='sc'>Viscera</span></td><td class='c010'><a href='#Page_77'>77</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>IX.</td><td class='c009'><span class='sc'>Organs of Reproduction; Pairing; Oviposition; Development</span></td><td class='c010'><a href='#Page_82'>82</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>X.</td><td class='c009'><span class='sc'>Habits</span></td><td class='c010'><a href='#Page_91'>91</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>XI.</td><td class='c009'><span class='sc'>Parasites</span></td><td class='c010'><a href='#Page_107'>107</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>XII.</td><td class='c009'><span class='sc'>Distribution</span></td><td class='c010'><a href='#Page_118'>118</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>XIII.</td><td class='c009'><span class='sc'>Snakes in Relation to Man</span></td><td class='c010'><a href='#Page_133'>133</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c007' colspan='3'>SYSTEMATIC ACCOUNT OF THE SNAKES</td></tr>
<tr><td class='c007' colspan='3'>OF EUROPE</td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c007' colspan='3'><span class='sc'>First Family</span>: TYPHLOPIDÆ</td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> TYPHLOPS, <span class='sc'>Schneider</span></td><td class='c010'><a href='#Page_144'>144</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>1.</td><td class='c009'><span class='sc'>Typhlops vermicularis</span>, Merrem—The Greek Blind-Snake</td><td class='c010'><a href='#Page_144'>144</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c007' colspan='3'><span class='sc'>Second Family</span>: BOIDÆ</td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> ERYX, <span class='sc'>Daudin</span></td><td class='c010'><a href='#Page_147'>147</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>2.</td><td class='c009'><span class='sc'>Eryx jaculus</span>, Linnæus—The Javelin Sand-Boa</td><td class='c010'><a href='#Page_147'>147</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c007' colspan='3'><span class='sc'>Third Family</span>: COLUBRIDÆ</td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> TROPIDONOTUS, <span class='sc'>Kuhl</span></td><td class='c010'><a href='#Page_152'>152</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>3.</td><td class='c009'><span class='sc'>Tropidonotus natrix</span>, Linnæus—The Grass-Snake,</td><td class='c010'></td></tr>
<tr><td class='c008'></td><td class='c009'>or Ring-Snake</td><td class='c010'><a href='#Page_152'>152</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>4.</td><td class='c009'><span class='sc'>Tropidonotus tessellatus</span>, Laurenti—The Tessellated</td><td class='c010'></td></tr>
<tr><td class='c008'></td><td class='c009'>Water-Snake</td><td class='c010'><a href='#Page_160'>160</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>5.</td><td class='c009'><span class='sc'>Tropidonotus viperinus</span>, Latreille—The Viperine</td><td class='c010'></td></tr>
<tr><td class='c008'></td><td class='c009'>Water-Snake</td><td class='c010'><a href='#Page_165'>165</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> ZAMENIS, <span class='sc'>Wagler</span></td><td class='c010'><a href='#Page_170'>170</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>6.</td><td class='c009'><span class='sc'>Zamenis gemonensis</span>, Laurenti—The European Whip-Snake</td><td class='c010'><a href='#Page_170'>170</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>7.</td><td class='c009'><span class='sc'>Zamenis dahlii</span>, Fitzinger—Dahl’s Whip-Snake</td><td class='c010'><a href='#Page_177'>177</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>8.</td><td class='c009'><span class='sc'>Zamenis hippocrepis</span>, Linnæus—The Horseshoe Whip-Snake</td><td class='c010'><a href='#Page_179'>179</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> COLUBER, <span class='sc'>Linnæus</span></td><td class='c010'><a href='#Page_181'>181</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>9.</td><td class='c009'><span class='sc'>Coluber quatuorlineatus</span>, Lacepède—Aldrovandi’s Snake</td><td class='c010'><a href='#Page_182'>182</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>10.</td><td class='c009'><span class='sc'>Coluber dione</span>, Pallas—The Dione Snake</td><td class='c010'><a href='#Page_185'>185</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>11.</td><td class='c009'><span class='sc'>Coluber longissimus</span>, Laurenti—The Æsculapian Snake</td><td class='c010'><a href='#Page_187'>187</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>12.</td><td class='c009'><span class='sc'>Coluber leopardinus</span>, Bonaparte—The Leopard Snake</td><td class='c010'><a href='#Page_191'>191</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>13.</td><td class='c009'><span class='sc'>Coluber scalaris</span>, Schinz—The Ladder Snake</td><td class='c010'><a href='#Page_194'>194</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> CORONELLA, <span class='sc'>Laurenti</span></td><td class='c010'><a href='#Page_196'>196</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>14.</td><td class='c009'><span class='sc'>Coronella austriaca</span>, Laurenti—The Smooth Snake</td><td class='c010'><a href='#Page_197'>197</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>15.</td><td class='c009'><span class='sc'>Coronella girondica</span>, Daudin—The Southern Smooth Snake</td><td class='c010'><a href='#Page_202'>202</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> CONTIA, <span class='sc'>Baird and Girard</span></td><td class='c010'><a href='#Page_205'>205</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>16.</td><td class='c009'><span class='sc'>Contia modesta</span>, Martin—The Dwarf Snake</td><td class='c010'><a href='#Page_205'>205</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> CŒLOPELTIS, <span class='sc'>Wagler</span></td><td class='c010'><a href='#Page_207'>207</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>17.</td><td class='c009'><span class='sc'>Cœlopeltis monspessulana</span>, Hermann—The Montpellier Snake</td><td class='c010'><a href='#Page_208'>208</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> MACROPROTODON, <span class='sc'>Guichenot</span></td><td class='c010'><a href='#Page_212'>212</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>18.</td><td class='c009'><span class='sc'>Macroprotodon cucullatus</span>, I. Geoffroy—The False</td><td class='c010'></td></tr>
<tr><td class='c008'></td><td class='c009'>Smooth Snake</td><td class='c010'><a href='#Page_213'>213</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> TARBOPHIS, <span class='sc'>Fleischmann</span></td><td class='c010'><a href='#Page_216'>216</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>19.</td><td class='c009'><span class='sc'>Tarbophis fallax</span>, Fleischmann—The Cat-Snake</td><td class='c010'><a href='#Page_217'>217</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>20.</td><td class='c009'><span class='sc'>Tarbophis iberus</span>, Eichwald—The Caucasian Cat-Snake</td><td class='c010'><a href='#Page_219'>219</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c007' colspan='3'><span class='sc'>Fourth Family</span>: VIPERIDÆ</td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> VIPERA, <span class='sc'>Laurenti</span></td><td class='c010'><a href='#Page_221'>221</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>21.</td><td class='c009'><span class='sc'>Vipera ursinii</span>, Bonaparte—Orsini’s Viper</td><td class='c010'><a href='#Page_221'>221</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>22.</td><td class='c009'><span class='sc'>Vipera renardi</span>, Christoph—Renard’s Viper</td><td class='c010'><a href='#Page_227'>227</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>23.</td><td class='c009'><span class='sc'>Vipera berus</span>, Linnæus—The Northern Viper, or Adder</td><td class='c010'><a href='#Page_230'>230</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>24.</td><td class='c009'><span class='sc'>Vipera aspis</span>, Linnæus—The Asp Viper</td><td class='c010'><a href='#Page_239'>239</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>25.</td><td class='c009'><span class='sc'>Vipera latastii</span>, Bosca—Lataste’s Viper</td><td class='c010'><a href='#Page_247'>247</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>26.</td><td class='c009'><span class='sc'>Vipera ammodytes</span>, Linnæus—The Sand-Viper, or</td><td class='c010'></td></tr>
<tr><td class='c008'></td><td class='c009'>Long-Nosed Viper</td><td class='c010'><a href='#Page_249'>249</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>27.</td><td class='c009'><span class='sc'>Vipera lebetina</span>, Linnæus—The Blunt-Nosed Viper, or Kufi</td><td class='c010'><a href='#Page_257'>257</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Genus</span> ANCISTRODON, <span class='sc'>Palisot de Beauvois</span></td><td class='c010'><a href='#Page_261'>261</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>28.</td><td class='c009'><span class='sc'>Ancistrodon halys</span>, Pallas—Pallas’s Pit-Viper</td><td class='c010'><a href='#Page_262'>262</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Index</span></td><td class='c010'><a href='#Page_265'>265</a></td></tr>
</table>

<div class='nf-center-c0'>
<div class='nf-center c002'  >
    LIST OF PLATES
  </div>
</div>

<table class='c006' summary='List of Plates'>
<tr><td class='c008'></td><td class='c009'><span class='smaller'>PLATE</span></td><td class='c011'><span class='smaller'>FACING PAGE</span></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>I.</td><td class='c009'><span class='sc'>Typhlops vermicularis, Eryx jaculus</span></td><td class='c011'><a href='#Page_144'>144</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>II.</td><td class='c009'><span class='sc'>Tropidonotus natrix and Vars. cettii and persa</span></td><td class='c011'><a href='#Page_152'>152</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>III.</td><td class='c009'><span class='sc'>Tropidonotus tessellatus, T. viperinus and</span></td><td class='c011'></td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>var. aurolineatus</span></td><td class='c011'><a href='#Page_160'>160</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>IV.</td><td class='c009'><span class='sc'>Zamenis gemonensis and vars. persica and</span></td><td class='c011'></td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>viridiflavus</span></td><td class='c011'><a href='#Page_170'>170</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>V.</td><td class='c009'><span class='sc'>Zamenis gemonensis, var. caspius, Z. dahlii,</span></td><td class='c011'></td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>Z. hippocrepis</span></td><td class='c011'><a href='#Page_176'>176</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>VI.</td><td class='c009'><span class='sc'>Coluber quatuorlineatus and var. sauromates,</span></td><td class='c011'></td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>C. dione</span></td><td class='c011'><a href='#Page_182'>182</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>VII.</td><td class='c009'><span class='sc'>Coluber longissimus, C. leopardinus and</span></td><td class='c011'></td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>var. quadrilineatus</span></td><td class='c011'><a href='#Page_188'>188</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>VIII.</td><td class='c009'><span class='sc'>Coluber scalaris</span></td><td class='c011'><a href='#Page_194'>194</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>IX.</td><td class='c009'><span class='sc'>Coronella austriaca</span></td><td class='c011'><a href='#Page_196'>196</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>X.</td><td class='c009'><span class='sc'>Coronella girondica, Contia modesta</span></td><td class='c011'><a href='#Page_202'>202</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>XI.</td><td class='c009'><span class='sc'>Cœlopeltis monspessulana, Macroprotodon</span></td><td class='c011'></td></tr>
<tr><td class='c008'></td><td class='c009'><span class='sc'>cucullatus, Tarbophis iberus, T. fallax</span></td><td class='c011'><a href='#Page_208'>208</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>XII.</td><td class='c009'><span class='sc'>Vipera ursinii, V. renardi, V. berus</span></td><td class='c011'><a href='#Page_220'>220</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>XIII.</td><td class='c009'><span class='sc'>Vipera aspis, V. latastii</span></td><td class='c011'><a href='#Page_240'>240</a></td></tr>
<tr><td>&nbsp;</td></tr>
<tr><td class='c008'>XIV.</td><td class='c009'><span class='sc'>Vipera lebetina, V. ammodytes, Ancistrodon halys</span></td><td class='c011'><a href='#Page_250'>250</a></td></tr>
</table>
<div class='pbb'></div>
<hr class='pb' />

<div class='nf-center-c0'>
<div class='nf-center c012'  >

<span class='pagenum'><a name='Page_1' id='Page_1'>1</a></span>
THE SNAKES OF EUROPE
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c013'  >
    INTRODUCTION
  </div>
</div>

<div class='chapter'>
  <h2 id='ch01' class='c014'>CHAPTER I<br /> <br />DEFINITION AND CLASSIFICATION</h2>
</div>
<p class='drop-capa c004'    >Snakes, <i>Ophidia</i>—regarded by some authorities
as an order of the class <i>Reptilia</i>, by the author
as a sub-order of the order <i>Squamata</i>, which includes
besides the Lizards, <i>Lacertilia</i>, the Chameleons,
<i>Rhiptoglossa</i>, and the extinct <i>Dolichosauria</i> and
<i>Mosasauria</i>—may be defined as greatly elongate
scaly Reptiles without limbs, or with mere vestiges
of the hind pair, without movable eyelids, without
ear-opening, with elongate, deeply forked tongue
retractile into a basal sheath, with transverse vent
and paired copulatory organs, and with the two
halves of the lower jaw independently movable,
connected at the symphysis by an elastic ligament.</p>

<p class='c005'>The latter character alone distinguishes them
from all Lizards, but no single Lizard possesses all
the others in combination.</p>

<p class='c005'>In their most highly developed form these Reptiles
are adapted for rapid reptation and for swallowing
<span class='pagenum'><a name='Page_2' id='Page_2'>2</a></span>
prey much exceeding their own calibre; hence the
bones of the skull, on which a prehensile function
devolves, are loosely attached to the cranium by
ligamentous elastic tissue, or articulated in such a
manner as to permit a wide buccal expansion; whilst
the absence of a sternum and the mobile attachment
of the ribs allow a corresponding dilatation of
the body as the prey descends into the digestive canal.</p>

<p class='c005'>The fatal venom which many of these Reptiles
possess has so impressed the mind of men, even the
scientific, that for a long time snakes were primarily
divided into poisonous and non-poisonous, a classification
in which the more important characters,
derived from the general structure, and especially
from the skull, were subordinated to the physiological.
Such a system was far from reflecting
natural relationships. Besides, as our knowledge
progressed, drawing a distinction between poisonous
and harmless snakes became more and more difficult,
so many snakes previously regarded as harmless
proving to be poisonous in various degrees—at least
enough to paralyze the small prey on which they
subsist, if not to be of serious danger to man.</p>

<p class='c005'>In the division into families, as followed in this
work, the presence or absence of a poison organ is
left out of consideration. Further, in this as in
many other groups of the animal kingdom, external
characters do not furnish trustworthy indications
for higher divisions, and the definitions of the
<span class='pagenum'><a name='Page_3' id='Page_3'>3</a></span>
families are therefore based exclusively on osteological
characters. For those who wish to name
snakes with facility, the key which concludes the
chapter on External Characters will, however, remedy
this defect, and suffice for the identification of all
the European species without any reference to their
anatomy. Many attempts have been made to
furnish an easy criterion for the distinction of harmless
from poisonous snakes, but the characters
hitherto suggested with this object can only be applied
successfully to the small number of representatives
in a limited area. Thus, in Southern Australia
it might be stated that all snakes showing the regular
nine large shields on the upper surface of the head
are dangerous to man, whilst those with small
shields or scales are harmless; but in most parts of
Europe this criterion would have to be reversed. In
some countries the shape of the pupil might be used
for the purpose, in others the size of the ventral
shields, or the presence or absence of a loreal shield,
between the nasal and the preocular, and so on.
But when we have to deal with the snakes of the
whole world, about 2,000 species, of which nearly
one-third are poisonous to a greater or less degree,
every attempt at a definition of the two categories
without regard to the dentition breaks down. Only
those who have made a study of the snakes of the
world can make a guess from the general appearance
as to an unknown form being poisonous or not, and
<span class='pagenum'><a name='Page_4' id='Page_4'>4</a></span>
even they may sometimes feel embarrassed, unless
the dentition be examined; the mistakes which
have occasionally been made by some experienced
herpetologists are proof sufficient of the fallacy of
external characters for this purpose.</p>

<p class='c005'>The Ophidia are divided into nine families, the
first, third, seventh, and ninth of which have representatives
in Europe:</p>

<p class='c015'>I. No transverse (ectopterygoid) bone; pterygoid
not extending to quadrate or mandible; no supratemporal;
nasals in contact with prefrontals;
coronoid present; vestiges of pelvis.</p>

<p class='c015'>Maxillary loosely attached to lower surface of
cranium, toothed; lower jaw edentulous; a single
pelvic bone</p>

<div class='nf-right-c0'>
  <div class='nf-right'>
    1. <span class='sc'>Typhlopidæ.</span>
  </div>
</div>

<p class='c015'>Maxillary bordering mouth, forming a suture with
premaxillary, prefrontal, and frontal, toothless;
pubis and ischium present, latter forming a symphysis</p>

<div class='nf-right-c0'>
  <div class='nf-right'>
    2. <span class='sc'>Glauconiidæ.</span>
  </div>
</div>

<p class='c015'>II. Transverse bone present; both jaws toothed.</p>
<p class='c016'><i>A.</i> Coronoid present; nasals in contact with prefrontals.</p>
<p class='c017'>1. Vestiges of pelvis; supratemporal present.</p>
<p class='c018'>Supratemporal large, suspending quadrate</p>

<div class='nf-right-c0'>
  <div class='nf-right'>
    3. <span class='sc'>Boidæ.</span>
  </div>
</div>

<p class='c019'>(Subfamilies: <i>Pythoninæ</i>, <i>Boinæ</i>.)</p>
<p class='c018'>Supratemporal small, intercalated in the cranial wall</p>

<div class='nf-right-c0'>
  <div class='nf-right'>
    4. <span class='sc'>Ilysiidæ.</span>
  </div>
</div>

<p class='c017'>
<span class='pagenum'><a name='Page_5' id='Page_5'>5</a></span>
2. No vestiges of pelvis; supratemporal absent</p>

<div class='nf-right-c0'>
  <div class='nf-right'>
    5. <span class='sc'>Uropeltidæ.</span>
  </div>
</div>

<p class='c016'><i>B.</i> Coronoid absent; supratemporal present.</p>
<p class='c017'>1. Maxillary horizontal; pterygoids reaching
quadrate or mandible.</p>
<p class='c018'>Nasals in contact with prefrontals</p>

<div class='nf-right-c0'>
  <div class='nf-right'>
    6. <span class='sc'>Xenopeltidæ.</span>
  </div>
</div>

<p class='c018'>Nasals not in contact with prefrontals</p>

<div class='nf-right-c0'>
  <div class='nf-right'>
    7. <span class='sc'>Colubridæ.</span>
  </div>
</div>

<p class='c015'>Three series: A. <i>Aglypha</i> (subfamilies: <i>Acrochordinæ</i>,
<i>Colubrinæ</i>, <i>Dasypeltinæ</i>); B. <i>Opisthoglypha</i>
(<i>Homalopsinæ</i>, <i>Dipsadomorphinæ</i>, <i>Elachistodontinæ</i>);
C. <i>Proteroglypha</i> (<i>Hydrophiinæ</i>, <i>Elapinæ</i>).</p>
<p class='c016'>2. Maxillary horizontal, converging posteriorly
towards palatine; pterygoid not reaching
quadrate or mandible</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    8. <span class='sc'>Amblycephalidæ.</span>
  </div>
</div>

<p class='c016'>3. Maxillary vertically erectile perpendicularly to
transverse bone; pterygoid reaching quadrate
or mandible</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    9. <span class='sc'>Viperidæ.</span>
  </div>
</div>

<p class='c021'>(Subfamilies: <i>Viperinæ</i>, <i>Crotalinæ</i>.)</p>

<p class='c005'>The technical terms employed in the above
synopsis will be found explained and illustrated by
figures in the chapter on the Skeleton.</p>

<p class='c005'>No serial arrangement can express the affinities
of the various groups as conceived by the classificator;
a diagram therefore follows to show the
author’s views as to their interrelationships, and
possibly their phylogeny. Leaving aside the
Typhlopidæ and Glauconiidæ, which should be regarded
<span class='pagenum'><a name='Page_6' id='Page_6'>6</a></span>
as burrowing types independently derived
from some Ophidian form less specialized than any
with which we are at present acquainted, and probably
without direct relationship to the Lizards, the
family Boidæ, and more especially the Pythons,
claim the position of ancestral group, from which
all other snakes may have been derived.</p>

<table
  class="tc" id = "famtree" summary="">
  <tr>
    <td colspan="2">Viperidæ</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td colspan="2">Amblycephalidæ</td>
  </tr>
  <tr>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td colspan="2">Colubridæ opisthoglyphæ</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td colspan="2">Colubridæ proteroglyphæ</td>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td class="bt">&nbsp;</td>
    <td class="bt">&nbsp;</td>
    <td class="bt">&nbsp;</td>
    <td class="bt br">&nbsp;</td>
    <td class="bt">&nbsp;</td>
    <td class="bt">&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td colspan="2">Uropeltidæ</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td colspan="2">Ilysiidæ</td>
    <td colspan="2">Xenopeltidæ</td>
    <td colspan="2">Colubridæ aglyphæ</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td class="br">&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td class="bt">&nbsp;</td>
    <td class="br bt">&nbsp;</td>
    <td class="bt">&nbsp;</td>
    <td class="bt">&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td colspan="2">Boidæ</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
    <td>&nbsp;</td>
  </tr>
</table>

<p class='c005'>Further remarks on this subject in the chapter
on Dentition.</p>

<p class='c005'>It is to be regretted that paleontology cannot
help us at present as concerns the lines of evolution,
the comparatively few fossil Ophidians known, from
the Lower Eocene upwards, the remains of which
can be identified with some measure of certainty,
being either non-poisonous types (<i>Boidæ</i>, <i>Ilysiidæ</i>,
<i>Palæophiidæ</i>, <i>Colubridæ</i>) or <i>Viperidæ</i> (Viperines from
the Miocene of France and Germany, Crotalines from
the Miocene of North America). The vertebræ from
the Puerco Eocene of America, on the limit between
the Cretaceous and Eocene periods, described as the
<span class='pagenum'><a name='Page_7' id='Page_7'>7</a></span>
oldest snake remains, <i>Helagras</i>, Cope, are stated to
approach the Lacertilian type.</p>

<p class='c005'>Whether the vertebræ named <i>Symoliophis</i>,
Sauvage, from the chalk of France, and <i>Coniophis</i>,
Marsh, from the Laramie Cretaceous of North
America, are Ophidian, as claimed by their describers,
or Dolichosaurian, cannot be decided without
further material.</p>

<div class='chapter'>

<span class='pagenum'><a name='Page_8' id='Page_8'>8</a></span>
  <h2 id='ch02' class='c003'>CHAPTER II<br /> <br />EXTERNAL CHARACTERS—INTEGUMENT</h2>
</div>
<p class='drop-capa c004'    >The form varies enormously, worm-like in some,
comparatively short and heavy, elongate and
more or less slender, or extremely gracile and almost
filiform, in others. In this respect our common Grass-snake
occupies a central position, and for this reason
is termed a moderately slender form, anything above
or below this standard being described as comparatively
short or elongate. Our shortest and
stoutest European Snakes are the Vipers, especially
<i>Vipera ursinii</i>; our longest and slenderest, the <i>Coluber</i>
and <i>Zamenis</i>, especially <i>Zamenis dahlii</i>. These
extremes in both directions are, however, far surpassed
by many exotic snakes, as we find on
comparing, for instance, one of the African Puff-adders
(<i>Bitis</i>), with certain <i>Oxybelis</i> and <i>Leptognathus</i>
from Tropical America. The body may be somewhat
rigid, as in some burrowing and ground snakes,
not unlike in appearance to our Slow-worm and other
limbless Lizards; or extremely flexible, as in many
Pythons and Boas and in the Tree-snakes generally.
This flexibility may be accompanied by a vertical
compression of the body in relation with an arboreal
existence, whilst sluggish snakes, such as most of the
<span class='pagenum'><a name='Page_9' id='Page_9'>9</a></span>
Viperidæ, may be remarkable for the flattening of
the body, which they may further increase when
basking in the sun or in order to assume a more
formidable appearance on the approach of an
enemy. This power of flattening out the whole or
the anterior part of the body is possessed by many
snakes, poisonous as well as harmless, and reaches
its highest degree in the Cobras of India and Africa,
the expanded anterior part being known as the
“hood,” from the Portuguese name “Cobra di
capello.”</p>

<p class='c005'>Thoroughly aquatic snakes are often short and
heavy, but some of the marine forms, or Hydrophids,
may be extremely slender, with the posterior part of
the body compressed. In some of these Sea-snakes
the gracility of the anterior part, or “neck,” as it
has been called, contrasts very strikingly with the
great girth of the body towards the tail, and suggests
a limbless Plesiosaur.</p>

<p class='c005'>The tail, the part of the body behind the transversely
cleft vent, is most frequently about one-fourth
or one-fifth of the total length; but it may be
much shorter, even reduced to a mere stump, as in
the <i>Typhlops</i>, or, at the opposite extreme, enter for
one half in the length of the snake, as in the
African <i>Xenurophis</i>. This organ may taper gradually
to a fine point; or end abruptly, as if mutilated; or
terminate in a horny spine, such as we see in some
of the <i>Typhlops</i> or in the Australian Death-adder,
<span class='pagenum'><a name='Page_10' id='Page_10'>10</a></span>
<i>Acanthophis</i>, or in a series of horny segments which
are vibrated like a rattle, as in the well-known
<i>Crotalus</i> of America, to which we shall refer again at
the end of this chapter. In some of the burrowing
Uropeltidæ, the very short tail is obliquely truncated,
with indurated shields above, and acts as a trowel.
And, finally, the marine snakes of the subfamily
Hydrophiinæ are distinguished by a strongly compressed,
oar-shaped tail, with rounded vertical
outline. In a few forms, arboreal or aquatic, the
tail is more or less prehensile.</p>

<p class='c005'>Males generally have a longer tail than females,
and the genital organs, which are lodged in its base,
cause a swelling of that region which contrasts with
the more gradually tapering extremity of the female,
thus affording a means of distinguishing the sexes
externally in the majority of snakes.</p>

<p class='c005'>The rudimentary hind limbs of Boid snakes, to be
mentioned further on in the description of the
skeleton, terminate in a claw-like horny spur, which
appears on each side of the vent in the male, and
sometimes also, though less distinctly, in the
female. These spurs are probably of use in facilitating
the pairing, an explanation which appears the
more plausible from the fact that the snakes provided
with them have the copulatory intromittent
organs destitute of the erectile spines which are
present in most others.</p>

<p class='c005'>The head varies in shape as much as the body.
<span class='pagenum'><a name='Page_11' id='Page_11'>11</a></span>
Although never actually compressed, except in the
rostral region, it may be very narrow and elongate,
whilst in the opposite extreme it may be strongly
depressed, and so broad behind as to be abruptly
defined from the anterior part of the body, or
“neck.” This feature is very marked in some of
the Viperidæ, and this has given rise to the incorrect
generalization that poisonous snakes are distinguished
from the harmless by a broad and flat
head, notwithstanding the fact that some of the
most dangerous, such as the Mambas, Cobras, and
Kraits, have a comparatively narrow or small head,
not or but slightly defined behind, whilst, on the
other hand, the very opposite condition obtains in
not a few of the harmless Colubrids.</p>

<p class='c005'>Leaving the Typhlopidæ and Glauconiidæ aside
for the present, snakes have a wide gape, cleft far
beyond the vertical of the eyes, with, when closed,
one or two notches in front for the passage of the
protrusible, bifid tongue. In most snakes this chink
is in the lower border of the rostral shield, capping
the tip of the snout, and allows free passage to the
whole tongue; in the Hydrophids, or Sea-snakes,
there are two notches in the lower border of the
rostral shield, through which only the bifid end
of the tongue can be protruded. The eyes, varying
from minute to enormous, are usually free from the
surrounding shields, and may move under a transparent
cap like a watch-glass, which appears to
<span class='pagenum'><a name='Page_12' id='Page_12'>12</a></span>
represent the lower eyelid of Lizards. The view as
to this homology is derived from our knowledge of
various conditions in certain series of Lizards of the
families Lacertidæ and Scincidæ, where we find a
transparent disc appearing like a small window in
the movable lower eyelid, gradually increasing in
size so as to occupy the whole of the lower eyelid,
which finally becomes fused with the rudimentary
upper lid and loses its mobility. In <i>Ilysia</i> and in
most of the Uropeltidæ, the transparent disc over
the eye is confluent with a thick horny shield of
which it occupies the middle.</p>

<p class='c005'>The pupil is usually circular or vertical, rarely
horizontal. In some forms it is difficult to decide
whether it is round or vertically elliptic; in others,
like the Boas and Vipers, for instance, it is decidedly
vertical, and contracts to the same extent as a cat’s.
In some Water-snakes, and in Sea-snakes generally,
the round pupil may contract to a mere dot. The contraction
of the pupil is independent on the two sides.</p>

<p class='c005'>The snout, or the part of the head anterior to the
eyes, may be short or long, rounded or pointed, depressed
or compressed, sometimes projecting strongly
beyond the mouth, turned up at the end, or terminating
in one (<i>Langaha</i>) or two (<i>Herpeton</i>) long
scaly dermal appendages. In some burrowing forms
it is provided with a more or less trenchant horizontal
or vertical edge. When the sides of the snout
(loreal region) form an angle with the upper surface,
<span class='pagenum'><a name='Page_13' id='Page_13'>13</a></span>
the angle is termed the “canthus rostralis,” which
may be intensified by the loreal region being concave.</p>

<p class='c005'>The deep pits which are sometimes present on
the lips or between the nostril and the eye (loreal
pit) will be alluded to further on under Sensory
Organs.</p>

<p class='c005'>The nostrils are either lateral, or, in the aquatic
forms, directed upwards, sometimes entirely on the
upper surface of the snout.</p>

<p class='c005'>Most snakes have a longitudinal groove on the chin
(mental groove) to allow for the distension caused by
the lateral movements of the rami of the lower jaw.</p>

<p class='c005'>In the Typhlopidæ, the head passes gradually into
the vermiform body, and the small mouth is situated
on the under surface of the projecting snout; the
head so resembles the extremely short tail, and the
mouth is so similar in shape and position to the vent,
which is close to the posterior extremity of the snake,
that such creatures are often believed by non-critical
observers to have a head at each end. The eyes are
very small, and covered over by the semi-transparent
head-shields, or they may be completely concealed.
There is no mental groove. It is much the same
with the Glauconiidæ, which have, however, a somewhat
less abbreviated tail. In both, the nostrils
often open on the lower side of the snout, which may
be excavated so as to appear hooked in profile, or
may be provided with a sharp cutting horizontal
edge.</p>

<p class='c005'>
<span class='pagenum'><a name='Page_14' id='Page_14'>14</a></span>
Snakes are covered with epidermal folds in the form
of scales and shields, the shape and arrangement of
which affords important characters for their classification.
Dermal ossifications are absent.</p>

<p class='c005'>The scales on the body are usually elliptic or
lanceolate and imbricate, forming straight longitudinal
and oblique transverse series, and they are replaced
on the belly and under the tail by transverse shields
mostly corresponding in number with the series of
scales, and also with the vertebræ. The body of the
Typhlopidæ and Glauconiidæ is uniformly covered
with polished, closely adherent, rounded, overlapping,
sub-equal scales, without even an indication of ventral
shields. In some of the Acrochordinæ, aberrant
aquatic Colubrids, the scaling consists, above and
beneath, of small juxtaposed, sometimes spinose
granules, the skin being suggestive of the shagreen of
sharks. In the marine snakes of the subfamily
Hydrophiinæ, the ventral shields are often absent or
merely indicated, and the scales are mostly juxtaposed
or feebly imbricate, sometimes tetragonal or hexagonal,
and occasionally studded with spinose tubercles.
In the more typical Ophidia the imbricate scales may
be long and narrow or short and broad, with every
intermediate step between the two extremes; smooth
or furnished with a longitudinal ridge or keel, or even
several keels; nearly equal in size or with the median
or outer series more or less enlarged, the longitudinal
series in odd, rarely in even number; instead of running
<span class='pagenum'><a name='Page_15' id='Page_15'>15</a></span>
in longitudinal series parallel with the axis of
the body, as is the rule, they are sometimes disposed
obliquely, and among those in which we meet with
this peculiarity several genera are further remarkable
in having some of the oblique lateral scales furnished
with a serrated keel, to which we shall again allude
in the chapter on Habits, when dealing with the
rustling sounds produced by certain snakes. The
number of longitudinal series of scales on the body
varies from 10 (<i>Herpetodryas</i>) to nearly 100 (<i>Python</i>,
<i>Boa</i>); in the European species from 17 (<i>Contia
modesta</i>) to 50 (<i>Eryx jaculus</i>). The scales are sometimes
furnished near the end with one or two shallow
impressions, termed “apical pits,” which afford indications
for the distinction of genera and species; unless
of a lighter or darker colour, as is often the case,
these pits are not always easy to see, except in a
strong light and with the aid of a powerful magnifying
glass.</p>

<p class='c005'>The ventral shields, also called “gastrosteges,”
usually occupy the whole width of the belly; but
they may be much narrower—in <i>Eryx</i>, for instance.
They are sometimes bent at an angle on the sides, and
this angle may even form a sharp keel, accompanied
by a notch in the posterior border, corresponding to
the keel, as in several of the more arboreal genera of
Colubrids. The shields under the tail, termed subcaudals
or “urosteges,” are sometimes similar to the
ventrals, but more often disposed in pairs; in certain
<span class='pagenum'><a name='Page_16' id='Page_16'>16</a></span>
species or individuals some of the subcaudals are
single, and the others paired. When the number of
subcaudals is given in the descriptions, each pair is
reckoned as one, and the conical or spine-like shield
which caps the end of the tail is not included. These
numbers afford important characters for the definition
of species, and sometimes also for the distinction of
sexes. The subcaudals are nearly always much fewer
than the ventrals, but the difference is often not so
great in the males as in the females, the tail of
which is usually shorter in proportion to the body. It
is noteworthy that in many species, if the number of
subcaudals (C.) be added to that of the ventrals (V.),
the total is nearly the same in the male as in the
female, however much the respective numbers may
differ when taken separately. The following figures
may be given by way of example, taken from British
specimens:</p>

<table class='c006' summary='Numbers of Ventrals and Subcaudals'>
<tr><td class='c022'><i>Coronella austriaca</i>:</td><td class='c009'>♂</td><td class='c009'><i>V.</i> 154;</td><td class='c011'><i>C.</i> 58 = 212</td></tr>
<tr><td class='c022'><i>Coronella austriaca</i>:</td><td class='c009'>♀</td><td class='c009'><i>V.</i> 165;</td><td class='c011'><i>C.</i> 48 = 213</td></tr>
<tr><td class='c022'><i>Vipera berus</i>:</td><td class='c009'>♂</td><td class='c009'><i>V.</i> 138;</td><td class='c011'><i>C.</i> 35 = 173</td></tr>
<tr><td class='c022'><i>Vipera berus</i>:</td><td class='c009'>♀</td><td class='c009'><i>V.</i> 144;</td><td class='c011'><i>C.</i> 29 = 173</td></tr>
</table>

<p class='c005'>Although this rule is by no means universal, and
does not apply at all to some species, it will be found
to hold good in many cases, and is of interest in
showing that the changes that have taken place in
the vertebral column (the vertebræ corresponding in
number to the shields), according to the sexes, have
<span class='pagenum'><a name='Page_17' id='Page_17'>17</a></span>
been by a modification of the character of the segments
about the anal region, a conversion of trunk
vertebræ into caudals, or <i>vice versa</i>. In dealing with
certain species—of Vipers, for instance—it is important,
for systematic purposes, to keep the counts of
shields distinct for the two sexes.</p>

<p class='c005'>The shield which covers the vent, the anal shield,
is either single or divided into two.</p>

<p class='c005'>Some snakes have the head covered with scales or
small tubercles similar to those on the body, but in
the great majority the lepidosis is in the form of
large symmetrical juxtaposed shields, the shape, proportions,
and number of which furnish some of the
most important characters for the distinction of
genera and species. These head-shields belong to
two primarily different types, from each of which all
further modifications may be regarded as derived by
alteration in shape or by disintegration. The first
type is that shown by the Typhlopidæ and Glauconiidæ,
which is explained by the figure on the
next page.</p>

<p class='c005'>The rostral, which is usually the largest of the head-shields,
extends to the upper surface of the head, of
which it may occupy the greater part. In the
Glauconiidæ, the ocular usually borders the mouth.</p>

<p class='c005'>As may be seen by a comparison of the first figure
with the second, the arrangement of the head-shields
is essentially different from that which prevails in the
Colubrids and the majority of other snakes.</p>

<p class='c005'>
<span class='pagenum'><a name='Page_18' id='Page_18'>18</a></span>
The second type is exemplified by the head of a
member of the genus <i>Zamenis</i>.</p>

<p class='c005'>In the descriptions, temporals 2 + 3 means two
superposed temporals in the first row, three in the
second. The internasals and the temporals, and the
loreal and the preocular, are sometimes absent, and
the prefrontal or the internasal may be single. One
or two large shields are in rare cases present behind
the parietals, and are called occipital.</p>

<p><a id='f01' name='f01' href='#f01'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_031.png' width="400" height="164"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 1</span>—<span class='sc'>Head of</span> <i>Typhlops braminus</i>. (From “Fauna of
British India”)</p>
<p class='hi-caption'><i>f</i>, Frontal; <i>ip</i>, interparietal; <i>l</i>, labial; <i>n</i>, nasal; <i>o</i>, ocular;
<i>p</i>, parietal; <i>po</i>, preocular; <i>prf</i>, prefrontal; <i>r</i>, rostral; <i>so</i>, supraocular.</p>
</div>

<p class='c005'>A breaking up into smaller shields takes place in
many snakes. In the Pythons, for instance, the
frontal may be divided into two by a longitudinal
cleft, and separated from the prefrontals by small
shields. In some Vipers, such as <i>V. berus</i> and
<i>V. ursinii</i>, in which the frontal and parietals, though
reduced in size, usually preserve their primitive
condition, the former is normally separated from the
supraocular by a series of small shields, and the
internasals and prefrontals are broken up; in these
<span class='pagenum'><a name='Page_19' id='Page_19'>19</a></span>
snakes the small shield or shields behind the
rostral are termed “apical,” and those on the upper
edge of the snout are termed “canthals.” The shield
which, in Vipers, separates the rostral from the nasal is
called “naso-rostral.” Allusion has been made above
to the scaly dermal appendages which terminate the
snout in certain genera. Some Viperidæ are furnished
<span class='pagenum'><a name='Page_20' id='Page_20'>20</a></span>
with horn-like erect spines above the eyes or at the
end of the snout, which add greatly to their sinistral
appearance.</p>

<p><a id='f02' name='f02' href='#f02'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_032.png' width="400" height="449"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 2</span>—<span class='sc'>Head of</span> <i>Zamenis ventrimaculatus</i>. (From “Fauna of
British India”)</p>

<p class='hi-caption'><i>cs</i>, Chin-shields (anterior); <i>cs´</i>, chin-shields (posterior); <i>f</i>, frontal;
<i>in</i>, internasal; <i>l</i>, loreal; <i>la</i>, labial (upper); <i>la´</i>, labial (lower);
<i>m</i>, mental; <i>n</i>, nasal; <i>p</i>, parietal; <i>pf</i>, prefrontal; <i>pro</i>, preocular;
<i>pto</i>, postocular; <i>r</i>, rostral; <i>sbo</i>, subocular; <i>so</i>, supraocular;
<i>t</i>, temporals (first row); <i>t´</i>, temporals (second row); <i>v</i>, first
ventral.</p>
</div>

<p class='c005'>The periodical shedding of the outer layer of the
epidermis in a single piece, including even the
covering of the eye, is one of the most striking
peculiarities of snakes, although paralleled in the
Lizards of the family Anguidæ, to which our
British Slow-worm belongs. The skin becomes
detached at the lips, and is turned inside out
from head to tail, without any sort of laceration
when the snake is in good health. These exuviæ are
transparent, but often carry a certain amount of
pigment, especially those of the Vipers, in which the
characteristic dark markings are perfectly visible;
they usually exceed the length of the reptile, owing
to stretching. In Sea-snakes the epidermis is cast
piecemeal, and sloughing is a longer operation than
in ordinary snakes.</p>

<p class='c005'>In Rattlesnakes each piece of the rattle, or
“crotalon,” in which the tail terminates, represents
a retained portion of the sloughed epidermis. This
remarkable appendage looks like a number of horny
rings, but it consists in reality of hollow, bell-like
pieces, similar to the terminal one, or “button,” each
with a circular constriction, in which the incurved
free edge of the following piece fits, thus keeping the
pieces together without impairing the mobility
necessary to produce the rattling sound for which
<span class='pagenum'><a name='Page_21' id='Page_21'>21</a></span>
the apparatus is intended. At each exuviation one
bell-shaped horny piece is added. The number of
segments in the rattle is, therefore, not an index to
age, as formerly believed; nor is it to the number of
exuviations, for whilst segments are being added at
the base of the apparatus the terminal ones break
off and are lost. A <i>Crotalus</i> sixteen months old may
have six pieces to the rattle if there have been six
exuviations and no loss. No rattle appears ever to
comprise more than about twenty pieces, even in old
specimens. The size of the terminal button shows
whether it was formed at birth or at any later period,
no growth taking place in the horny tissue.</p>

<p class='c005'>So far as trustworthy records are concerned, the
largest snakes known, the Malay <i>Python reticulatus</i>
and the South American Anaconda, <i>Eunectes murinus</i>,
reach a length of 25 to 30 feet. Measurements of
skins must be accepted with caution, as a skin may
easily be stretched to once and a half its real length;
in estimating the exact length from such a stretched
skin, it is necessary to deduct the interstitial spaces
showing between the scales, and about one-fourth of
the scale to allow for the overlap. The smallest
snake known is 4 inches long (<i>Glauconia dissimilis</i>).
The largest European snake (<i>Coluber quatuorlineatus</i>)
is reported to reach a length of 8 feet; the smallest
(<i>Typhlops vermicularis</i>) does not exceed 14 inches.</p>

<div class='nf-center-c0'>
<div class='nf-center c023'  >

<span class='pagenum'><a name='Page_22' id='Page_22'>22</a></span>
<span class='sc'>Key to the Identification of the European Snakes from External Characters only</span>
  </div>
</div>

<p class='c015'>I. Eyes minute, under the head-shields; mouth
small, inferior; body vermiform, covered with
uniform scales above and beneath; vent close to
the end of the body, the extremely short tail
ending in a small spine</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Typhlops vermicularis.</i>
  </div>
</div>

<p class='c015'>II. Eyes very small, with vertical pupil; upper
surface of head covered with small scales;
ventral shields much narrower than the body;
tail short, ending obtusely; subcaudals single, or
mostly single; scales smooth or feebly keeled, in
40 to 50 rows</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Eryx jaculus.</i>
  </div>
</div>

<p class='c015'>III. Eyes small, moderate, or large; ventral shields
at least nearly as broad as the body; tail tapering
to a point; subcaudals paired.</p>
<p class='c016'><i>A.</i> Pupil round; upper surface of head with nine
large shields; no upper labial in contact with
the parietal; anal shield usually divided.</p>
<p class='c017'>1. Dorsal scales strongly keeled, with paired
apical pits; a single anterior temporal.</p>
<p class='c025'><i>a.</i> Nostrils lateral; internasals broadly truncate
in front.</p>
<p class='c015'>Scales in 19 rows; normally 1 pre- and 3 postoculars;
usually 7 upper labials, third and fourth
entering the eye; ventrals 157-181; subcaudals
50-88</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Tropidonotus natrix.</i>
  </div>
</div>

<p class='c025'>
<span class='pagenum'><a name='Page_23' id='Page_23'>23</a></span>
<i>b.</i> Nostrils directed upwards; internasals
much narrowed in front.</p>
<p class='c015'>Scales in 19 rows; normally 2 pre- and 3 or 4 postoculars;
suboculars sometimes present; usually
8 upper labials, fourth or fourth and fifth entering
the eye; ventrals 160-187; subcaudals 48-79</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Tropidonotus tessellatus.</i>
  </div>
</div>

<p class='c015'>Scales in 21 (rarely 19 or 23) rows; normally 1 or 2
pre- and 2 postoculars; usually 7 upper labials,
third and fourth entering the eye; ventrals
147-164; subcaudals 46-72</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Tropidonotus viperinus.</i>
  </div>
</div>

<p class='c017'>2. Dorsal scales smooth or feebly keeled;
normally a single loreal.</p>
<p class='c025'><i>a.</i> Two or three superposed anterior temporals
(very rarely one); nostril usually
between two nasals.</p>
<p class='c026'>α. A subocular below the preocular.</p>

<p class='c027'>* Scales smooth, in 17 or 19 rows.</p>

<p class='c015'>Two upper labials entering the eye; preocular not
in contact with the frontal; scales with two apical
pits; ventrals more or less distinctly angulate
laterally, 160-230; subcaudals 87-131</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Zamenis gemonensis.</i>
  </div>
</div>

<p class='c015'>Two upper labials entering the eye; preocular usually
in contact with the frontal; scales with a single
apical pit; ventrals very distinctly angulate laterally,
205-218; subcaudals 98-132</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Zamenis dahlii.</i>
  </div>
</div>

<p class='c028'>** Scales in 23 to 29 rows (usually 25 or
27), with two apical pits.</p>

<p class='c015'>
<span class='pagenum'><a name='Page_24' id='Page_24'>24</a></span>
Upper labials usually separated from the eye by a
series of suboculars; preocular in contact with
the frontal; scales smooth; ventrals very distinctly
angulate laterally, 222-258; subcaudals
77-107</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Zamenis hippocrepis.</i>
  </div>
</div>

<p class='c015'>Two upper labials entering the eye; preocular not
in contact with the frontal; scales feebly but distinctly
keeled; ventrals not angulate laterally,
195-234; subcaudals 56-90</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coluber quatuorlineatus.</i>
  </div>
</div>

<p class='c015'>Two upper labials entering the eye; preocular not
in contact with the frontal; scales smooth or
faintly keeled; ventrals not or but very obtusely
angulate laterally, 172-214; subcaudals 50-80</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coluber dione.</i>
  </div>
</div>

<p class='c026'>β. No subocular; scales smooth, or faintly
keeled on the posterior part of the body.</p>
<p class='c028'>* Ventrals more than 200; scales with
two apical pits.</p>

<p class='c015'>Snout obtuse; rostral broader than deep; scales in
21 or 23 rows; ventrals distinctly angulate laterally,
212-248; subcaudals 60-91</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coluber longissimus.</i>
  </div>
</div>

<p class='c015'>Snout obtuse; rostral broader than deep; scales in
25 or 27 rows; ventrals not angulate laterally,
222-260; subcaudals 68-90</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coluber leopardinus.</i>
  </div>
</div>

<p class='c015'>Snout pointed, strongly projecting; rostral deeper
than broad, wedged in between the internasals;
scales in 25 to 29 rows; ventrals not angulate laterally,
201-220; subcaudals 48-68</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coluber scalaris.</i>
  </div>
</div>

<p class='c028'>
<span class='pagenum'><a name='Page_25' id='Page_25'>25</a></span>
** Ventrals not more than 200; scales
mostly with a single apical pit.</p>

<p class='c015'>Rostral at least as deep as broad, often wedged in
between the internasals; usually 7 upper labials,
third and fourth entering the eye; scales in 19
(rarely 21) rows; ventrals 153-199; subcaudals
41-70</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coronella austriaca.</i>
  </div>
</div>

<p class='c015'>Rostral broader than deep; usually 8 upper labials,
fourth and fifth entering the eye; scales in 21
(rarely 19 or 23) rows; ventrals 170-200; subcaudals
49-72</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coronella girondica.</i>
  </div>
</div>

<p class='c025'><i>b.</i> A single anterior temporal; nostril in a
single nasal; scales smooth, with single
apical pits, in 17 rows; ventrals 150-191;
subcaudals 53-78</p>

<div class='nf-right-c0'>
<div class='nf-right c029'  >
    <i>Contia modesta.</i>
  </div>
</div>

<p class='c017'>3. Scales longitudinally grooved in the adult, in
17 or 19 rows; two loreals; canthus rostralis
strongly marked; frontal very narrow, in
contact with the preocular; ventrals 160-189;
subcaudals 68-102</p>

<div class='nf-right-c0'>
<div class='nf-right c030'  >
    <i>Cœlopeltis monspessulana.</i>
  </div>
</div>

<p class='c016'><i>B.</i> Pupil vertical or vertically subelliptic (sometimes
appearing round in <i>Macroprotodon</i>).</p>

<p class='c017'>1. Scales smooth, mostly with single apical pits;
upper surface of head with nine large shields.</p>

<p class='c015'>Frontal
1<span class='nom'>1</span>⁄<span class='dem'>2</span>
to 2 times as long as broad; loreal separated
from the eye by the preocular; one upper labial
usually in contact with the parietal; scales in 19 to
23 (rarely 25) rows; ventrals 153-192; anal divided;
subcaudals 40-54</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Macroprotodon cucullatus.</i>
  </div>
</div>

<p class='c015'>
<span class='pagenum'><a name='Page_26' id='Page_26'>26</a></span>
Frontal
1<span class='nom'>1</span>⁄<span class='dem'>4</span> to
1<span class='nom'>1</span>⁄<span class='dem'>2</span>
times as long as broad, much
shorter than the parietals; loreal entering the
eye; scales oblique, in 19 or 21 rows; ventrals
186-222; anal divided; subcaudals 48-73</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Tarbophis fallax.</i>
  </div>
</div>

<p class='c015'>Frontal
1<span class='nom'>1</span>⁄<span class='dem'>4</span> to
1<span class='nom'>1</span>⁄<span class='dem'>2</span>
times as long as broad, nearly
as long as the parietals; loreal entering the eye;
scales oblique, in 19 or 21 rows; ventrals 203-235;
anal entire; subcaudals 54-70</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Tarbophis iberus.</i>
  </div>
</div>

<p class='c017'>2. Scales keeled, with two apical pits; anal
shield entire.</p>

<p class='c025'><i>a.</i> No pit between the nostril and the eye;
upper head-shields small, if present; nasal
separated from the rostral by a naso-rostral;
eye separated from the upper
labials by suboculars.</p>

<p class='c026'>α.
Snout not turned up at the end; supraocular
usually extending posteriorly
beyond the vertical of the posterior border
of the eye; frontal and parietal shields
usually well developed; usually a single
series of scales between the eye and the
upper labials.</p>

<p class='c015'>Snout obtusely pointed, flat above, or with the
canthus slightly raised; rostral usually in contact
with a single apical shield, rarely with two; 6 to 9
upper labials, usually 7 or 8; scales in 19 rows,
rarely 21; ventrals:
♂ 120-135, ♀ 125-142</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Vipera ursinii.</i>
  </div>
</div>

<p class='c015'>
<span class='pagenum'><a name='Page_27' id='Page_27'>27</a></span>
Snout pointed, with raised canthus; rostral in contact
with a single apical shield; 8 or 9 upper
labials; scales in 21 rows, rarely 19; ventrals:
♂ 130-148, ♀ 130-150</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Vipera renardi.</i>
  </div>
</div>

<p class='c015'>Snout truncate or broadly rounded, flat above or
with slightly raised canthus; rostral in contact
with two apical shields, rarely with one; 8 or 9
upper labials; scales in 21 rows, rarely 19 or 23;
ventrals:
♂ 132-150, ♀ 132-158</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Vipera berus.</i>
  </div>
</div>

<p class='c026'>β.
Snout usually more or less turned up at
the end or produced into a scaly dermal
appendage; supraocular not extending
posteriorly beyond the vertical of the posterior
border of the eye; frontal and
parietals often absent or very small;
2 or 3 series of scales between the eye and
the upper labials; 9 to 13 upper labials;
scales in 21 or 23 rows, rarely 19 or 25.</p>

<p class='c015'>Snout simply turned up, the raised portion bearing
2 or 3 scales; rostral not more than once and a half
as deep as broad; ventrals:
♂ 134-158, ♀ 141-169</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Vipera aspis.</i>
  </div>
</div>

<p class='c015'>Snout simply turned up or produced into a small
appendage, the raised portion with 5 or 6 (rarely 3)
scales; rostral
1<span class='nom'>1</span>⁄<span class='dem'>2</span>
to 2 times as deep as broad;
ventrals:
♂ 125-146, ♀ 135-147</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Vipera latastii.</i>
  </div>
</div>

<p class='c015'>Snout produced into an appendage covered with
10 to 20 scales; rostral not reaching the summit
of the rostral appendage; ventrals:
♂ 133-161, ♀ 135-163</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Vipera ammodytes.</i>
  </div>
</div>

<p class='c026'>
<span class='pagenum'><a name='Page_28' id='Page_28'>28</a></span>
γ.
Snout not turned up at the end; supraocular
narrow or broken up into several
small shields; upper surface of head
with small, usually keeled scales; two or
three series of scales between the eye and
the upper labials; scales in 23 to 27 rows,
usually 25; ventrals:
♂ 151-177, ♀ 153-180</p>

<div class='nf-right-c0'>
<div class='nf-right c031'  >
    <i>Vipera lebetina.</i>
  </div>
</div>

<p class='c025'><i>b.</i> A pit between the nostril and the eye;
upper surface of head with 9 large shields;
nasal in contact with the rostral; third
upper labial entering the eye; scales in
23 rows; ventrals 149-174; subcaudals
31-44</p>

<div class='nf-right-c0'>
<div class='nf-right c029'  >
    <i>Ancistrodon halys.</i>
  </div>
</div>

<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_29' id='Page_29'>29</a></span>
  <h2 id='ch03' class='c003'>CHAPTER III<br /> <br />COLORATION</h2>
</div>
<p class='drop-capa c004'    >In dealing with the coloration, we have first to
distinguish between the colour and the markings.
The former is very often highly variable among
snakes of the same species, to say nothing of the
changes which may take place with age or with
the condition of the individuals, whether before or
after exuviation; it is not unusual to find among
specimens from the same locality a great range of
variation, from greyish-white to brown, or red, or
black, as, for instance, in our Common Viper. The
latter afford more important characters, and often
furnish valuable indications for the distinction of
species; but even the disposition of the markings is
subject to great individual variations, more likely to
mislead than to help the inexperienced student in
the discrimination of species. It is therefore always
advisable to resort in the first instance to structural
characters for the purpose of specific identification,
and to fall back on coloration only as a means of
confirmation. If we were to be guided by colour
and markings alone, how could we believe that an
adult four-lined <i>Coluber quatuorlineatus</i> is of the
<span class='pagenum'><a name='Page_30' id='Page_30'>30</a></span>
same species as the handsomely spotted <i>Coluber
sauromates</i>; and yet, if we compare the young of
these two snakes we find them to be absolutely
identical in their markings, and, in the absence of
any structural differences, we are forced to conclude
that they only represent two forms of the same
species, of which the latter is the more primitive.</p>

<p class='c005'>It is nevertheless a fact that, with a few exceptions,
the markings, however variable they may be,
are reducible to certain fundamental patterns to
which the innumerable variations may be traced
back, and their derivation followed and scientifically
explained. Let us consider, for instance, another
species of <i>Coluber</i>, highly variable in its markings:
<i>C. leopardinus</i>, of which the typical form, so called
from having been the first described and named, is
not by any means to be regarded as the most
primitive.</p>

<p class='c005'>First, we must take for granted that the markings
of all such snakes, whether consisting of spots,
stripes, or bars, start from a regular arrangement,
which may be theoretically represented by four
paired longitudinal series on the head and body:
(1) Dorsal series (D); (2) Dorso-lateral (DL); (3)
Lateral (L); (4) Ventro-lateral (VL). The first
starts from the middle line of the head, and is continued
along the spine; the second occupies the
space between the first and third, which originates
at the tip of the snout, passes through the eye, and
<span class='pagenum'><a name='Page_31' id='Page_31'>31</a></span>
is continued on the temple and along the side of the
body; the fourth follows the lower lip, and extends
along each side of the belly. Bearing this in mind,
we find that the variety of <i>C. leopardinus</i> named
<i>schwoederi</i>, with a vertebral series of paired spots, is
to be regarded as the most primitive, from which we
can derive, on the one hand, the true <i>leopardinus</i> by
imagining a transverse fusion of the spots of series D
into a single row, some of the spots often actually
revealing, in their biscuit shape, their dual origin;
whilst, on the other hand, confluence of the paired
spots of the same series into two longitudinal stripes
produces the variety named <i>quadrilineatus</i> (see
<a href='#p07'>Plate VII</a>.). In this particular instance, the paired
series D has fused into a single streak on the head,
and the series L appears to have departed from its
primitive course to extend on the upper surface of
the head, both in front of and behind the eye.</p>

<p class='c005'>Many snakes show an interocular band extending
from lip to lip, through the eyes, across the interorbital
region. In others the lateral stripe L may
bifurcate in front of the eye, an upper branch
extending across the snout, through transverse
fusion of series D and DL, and it may also bifurcate
in like manner on the temporal region, fusing with
the corresponding marking on the other side to form
a <b>W</b>-shaped figure. The pattern of markings on the
upper surface of the head is, however, often very
complicated, and hence difficult of explanation.</p>

<p class='c005'>
<span class='pagenum'><a name='Page_32' id='Page_32'>32</a></span>
As a second example of the derivation of patterns,
we may mention <i>Vipera aspis</i>, which varies enormously
as to its mid-dorsal markings, forming, in
different individuals or even on different parts of the
body, single or paired spots, a zigzag band, or transverse
bars; all these are derived from the paired
spots of series D. Each pair of spots may fuse and
form transversely oval or elliptical spots or bars, or
the spots may assume an alternate disposition from
which, through confluence, the zigzag or sinuous
band results. Thus, spotted and striped patterns
may be traced to a common origin, however
fundamental the difference between them appears at
first sight. If the elements of the four series, D,
DL, L, and VL, unite transversely with each other,
and also with the spots on the ventral surface, we
obtain ringed forms such as the Coral-snakes.
That the black nuchal collar of our common Grass-snake
is actually formed by the fusion of the spots
of three originally distinct series has been proved by
tracing the development of the markings in the
embryo.</p>

<p class='c005'>In various species a pair of light streaks extends
along the back, bordering the D area, without interfering
with the other markings, as we see, among
European snakes, in some specimens of <i>Tropidonotus
natrix</i> and <i>viperinus</i>, and <i>Vipera berus</i>.</p>

<p class='c005'>Although it sometimes happens that a definite
system of markings prevails throughout a genus,
<span class='pagenum'><a name='Page_33' id='Page_33'>33</a></span>
such as the annulate form in the South American
<i>Elaps</i>, this is far from being universally the case;
many closely allied species, or individuals of the
same species, may be distinguished by very different
patterns. Even on the same individual we may find
two opposite types of markings without any transition,
as in two Central American species of widely
different genera, <i>Polyodontophis annulatus</i> and <i>Zamenis
mexicanus</i>, in which the anterior part of the body is
annulate or barred, and the rest longitudinally
striped.</p>

<p class='c005'>It is also a remarkable fact that very often the
two sides of the body are not alike in their markings,
appearing as if formed of the union, on the median
line, of the right and left halves of two individuals.
Thus it may happen, in annulate forms, that some of
the annuli are broken exactly in the mid-dorsal and
mid-ventral lines, and that the halves do not correspond
in number on the two sides. In the handsome
South American <i>Lachesis alternatus</i>, which
derives its specific name from the two series of
large <b>C</b>-shaped, dark, light-edged markings which
adorn its back, these markings are not always alternating,
as is the rule; but some may lie opposite
to each other and back to back, this being due to
the fact that the numbers of the markings do not
correspond on the two sides. In one specimen I
count twenty-four of these markings on the left side,
and twenty-seven on the right. This shows that
<span class='pagenum'><a name='Page_34' id='Page_34'>34</a></span>
great importance cannot be attached to the number
of the markings, for systematic purposes. In fact,
in some Coral-snakes, <i>Elaps fulvius</i> for instance, the
number of annuli may vary from twelve to fifty-two,
with every gradation between the extremes. The
bilateral asymmetry to which we have alluded produces
the chess-board arrangement of the ventral
spots in many snakes.</p>

<p class='c005'>Among the markings which call for investigation
as to their meaning, we must allude to the presence,
in some Colubrids, of a small, light, dark-edged spot,
or of a pair of light dots close together, in the
middle of the parietal shields or on each side of the
suture between these shields, which correspond in
their position to the parietal organ of many Lizards.
May not this marking be in some way correlated
with sensory organs, like the apical pits on the scales
of the body? And what is the explanation of such
bizarre signs as the spectacle or the eye-spot on the
hood of the Indian Cobra? At present it is as
inexplicable as the lugubrious emblem on the thorax
of the Death’s-head Moth. It cannot be suggested
that it is a warning mark intended to terrify intruders,
for when the Cobra is at rest the hood is folded, and
the characteristic marking is not displayed; whilst
as soon as it is aroused, and the hood expanded, it
faces its enemy in such a way that the spectacle, or
ocellus, is not to be seen.</p>

<p class='c005'>First among the most brilliantly coloured snakes,
<span class='pagenum'><a name='Page_35' id='Page_35'>35</a></span>
of which there are many, stand the Coral-snakes,
<i>Elaps</i>, of America, mostly annulate with red, yellow
or white, and black. This striking coloration obtains
also in diverse harmless snakes inhabiting the same
part of the world, and this coincidence has been
adduced in favour of the theory of mimicry, correlated
with that of natural selection, which accounts
for the resemblance as being of advantage to a
harmless species, which is thus mistaken for one
notorious for its deadly poison, and advertised as
such by its brilliant colours (warning coloration).
But other poisonous and much more dangerous
snakes are not, as a rule, endowed with brilliant
colours. It is true that these also may have their
mimics: the Krait, <i>Bungarus cæruleus</i>, and <i>Lycodon
aulicus</i>, in India, the Pit-viper, <i>Ancistrodon himalayanus</i>,
and <i>Psammodynastes pulverulentus</i>, in the
Himalayas and Assam, are good examples of such
cases. On the other hand, there are equally striking
instances of what one would regard as mimics if
they only occurred together; thus, there is no better
case of general resemblance between a poisonous
and a harmless snake than we find in the Indian
Cobra and the <i>Coluber corais</i> of tropical America,
where Cobras are absent, or between a Viper and
the Boid <i>Enygrus asper</i>, from New Guinea, where
no Vipers exist.</p>

<p class='c005'>Without attempting to offer any suggestion to
account for the similarity of markings which prevails
<span class='pagenum'><a name='Page_36' id='Page_36'>36</a></span>
in certain parts of the world, attention may be drawn
to the predominance of longitudinal dark and light
stripes in the Indo-Malayan representatives of the
American <i>Elaps</i>, shared by many innocuous snakes
of similar form inhabiting the same region, and
to the striped tails common to various Colubrids
of Madagascar, as if the snakes of a district had
agreed to conform to certain fashions in dress.</p>

<p class='c005'>It is further noteworthy, in relation to the theory of
warning coloration, that many Uropeltids, innocent
burrowing creatures living underground or concealed
under stones or rotting tree-trunks in the forests of
Southern India and Ceylon, hardly ever showing
themselves in daylight, are among the most striking
for their bright yellow or red and black markings.
We may point out at the same time the very marked
resemblance in form and coloration between the
Uropeltid <i>Melanophidium bilineatum</i>, and the Apodal
Batrachian <i>Ichthyophis glutinosus</i>, both occurring
together in Southern India.</p>

<p class='c005'>The colour of snakes often harmonizes with their
surroundings. Thus, many Tree-snakes, Boid, Colubrid,
or Viperid, are of a bright green, like the
foliage in which they are concealed. On the other
hand, other Tree-snakes are not green, or only some
specimens are green, as in the genera <i>Dendraspis</i> and
<i>Dispholidus</i>. Desert-snakes are of the yellowish or
reddish colour of the sand or rock on which they
live, and in species whose range extends over different
<span class='pagenum'><a name='Page_37' id='Page_37'>37</a></span>
districts the desert individuals are paler, without or
with less distinct markings, as compared to their
fellows among other surroundings. In addition to
their markings, some snakes are adorned with a
metallic iridescent gloss, due to a fine striation of
the scales.</p>

<p class='c005'>The iris is often metallic, gold, bronze, or copper-red,
and the black streaks of the head sometimes
extend over it.</p>

<p class='c005'>Although, unlike many lizards, snakes are unable
to rapidly alter their colours, some produce a
semblance of this phenomenon when inflating their
neck or body; this is due to the presence of dark
and light markings or of a bright pigment in the
interstitial skin, which is not seen when the scales
overlap. Thus, in the Indian Tree-snake <i>Dryophis
mycterizans</i> the skin between the green or brown
scales in the anterior part of the body is black
and white, producing a striped pattern when the
neck is inflated; the skin of the same region is
bright vermilion in the Malay <i>Tropidonotus subminiatus</i>;
many more examples could be quoted.
The spectacle marking on the hood of the Indian
Cobra involves the scales as well as the interstitial
skin.</p>

<p class='c005'>As a rule there are no sexual differences in colour.
Yet these are so marked in our Common Adder that
the sex of a specimen can nearly always be recognized
by the coloration. This is, however, the
<span class='pagenum'><a name='Page_38' id='Page_38'>38</a></span>
exception, even in the genus to which the Adder
belongs. A nuptial dress is unknown in snakes.</p>

<p class='c005'>A special livery for the young is rather exceptional,
but very often the new-born is more vividly coloured
than its parents, and in many black varieties the
young is similar to the typical form. Some green
Tree-Boids (<i>Chondropython</i> and <i>Corallus caninus</i>) are
not green, but yellowish, cream-colour, or pinkish,
when young, the green appearing around the white
spots, which are the remains of the ground colour, and
gradually spreading over the whole body. Conversely,
the young of a variety of the Pit-viper <i>Lachesis
wagleri</i>, common in the Malay Peninsula, is green,
and the adult black and yellow. In the young of
<i>Grayia ornata</i>, a West African Water-snake, the
markings of the young are to those of the adult
like positive and negative in photography, the white
bars, forked on the sides, which extend across the
black back of the former being gradually transformed
into black bars on a light ground in the
latter; in such a case it is impossible to decide
whether the dark or the light parts are to be considered
as the ground colour.</p>

<p class='c005'>That the skin of many snakes contains soluble
colouring matter of a special kind is well known,
green snakes, such as <i>Dryophis prasinus</i> and <i>Lachesis
gramineus</i> staining the spirit in which they are preserved.
Chemists have not yet paid attention to
this question, which requires investigation.</p>

<p class='c005'>
<span class='pagenum'><a name='Page_39' id='Page_39'>39</a></span>
Melanism is frequent in snakes, and sometimes
affects all individuals in the same locality. It
seems undesirable to bestow varietal names on such
aberrations, as is so frequently done by systematists,
any more than we should in the case of albinos.
Melanism may be produced in two ways: by an
extension of the black markings, which invade the
whole surface, as in the males of <i>Vipera berus</i>; or by
a general darkening of the ground colour and of the
markings, as in the females of the same species. In
the latter case, the markings reappear under certain
lights or after a prolonged sojourn in spirits. Sometimes,
as in <i>Zamenis gemonensis</i>, the uniform black
colour appears only as the snake approaches the
adult condition, the young having the normal
livery.</p>

<p class='c005'>Partial albinism is rare; perfect albinism, characterized
by absence of black pigment in the eye, rarer
still. Cases have been observed, among European
species, in <i>Tropidonotus natrix</i> and <i>tessellatus</i>, in
<i>Coluber longissimus</i>, and in <i>Coronella austriaca</i>.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_40' id='Page_40'>40</a></span>
  <h2 id='ch04' class='c003'>CHAPTER IV<br /> <br />SKELETON</h2>
</div>
<p class='drop-capa c004'    >The typical Ophidian skull is characterized by
a solidly ossified brain-case, with the distinct
frontals and the united parietals extending downwards
to the basisphenoid, which is large and produced
forward into a rostrum extending to the ethmoidal
region. The nasal region is less completely ossified,
and the paired nasals are often attached only at their
base. The occipital condyle is either trilobate and
formed by the basioccipital and the exoccipitals, or a
simple knob formed by the basioccipital; the supraoccipital
is excluded from the foramen magnum.
The basioccipital may bear a strong, curved ventral
process or hypapophysis (in the Vipers).</p>

<p class='c005'>The prefrontal is situated, on each side, between
the frontal and the maxillary, and may or may not
be in contact with the nasal; the postfrontal, usually
present, borders the orbit behind, rarely also above,
and in the Pythons a supraorbital is intercalated
between it and the prefrontal.</p>

<p><a id='f03' name='f03' href='#f03'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_054.jpg' width="400" height="458"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 3</span>—<span class='sc'>Skull of</span> <i>Python amethystinus</i>. (From British Museum
Catalogue of Snakes)</p>

<p class='hi-caption'><i>an</i>, Angular; <i>ar</i>, articular; <i>bo</i>, basioccipital; <i>bs</i>, basisphenoid;
<i>cor</i>, coronoid; <i>c.a</i>, columella auris (stapes); <i>d</i>, dentary; <i>eo</i>, exoccipital;
<i>epg</i>, ectopterygoid (transverse); <i>f</i>, frontal; <i>m</i>, maxillary;
<i>n</i>, nasal; <i>p</i>, parietal; <i>pl</i>, palatine; <i>pm</i>, premaxillary;
<i>prf</i>, prefrontal; <i>pro</i>, proötic; <i>pg</i>, pterygoid; <i>ptf</i>, postfrontal;
<i>q</i>, quadrate; <i>so</i>, supraoccipital; <i>sor</i>, supraorbital; <i>sp</i>, splenial;
<i>ste</i>, supratemporal; <i>tu</i>, turbinal; <i>v</i>, vomer.</p></div>

<p class='c005'>The premaxillary is single and small, and as a
rule connected with the maxillary only by ligament.
The paired vomer is narrow. The palatine and
<span class='pagenum'><a name='Page_42' id='Page_42'>42</a></span>
pterygoid are elongate and parallel to the axis
of the skull, the latter diverging behind and extending
to the quadrate or to the articular extremity
of the mandible; the pterygoid is connected with
the maxillary by the ectopterygoid or transverse
bone, which may be very elongate, and the maxillary
often emits a process towards the palatine, the latter
bone being usually produced inwards and upwards
towards the anterior extremity of the basisphenoid.
The quadrate is usually large and elongate, and
attached to the cranium through the supratemporal
(often regarded as the squamosal). In rare cases
(<i>Miodon</i>, <i>Polemon</i>) the transverse bone is forked, and
articulates with two branches of the maxilla. The
quadrate and the maxillary and palatopterygoid
arches are more or less movable to allow for the
distension required by the passage of prey, often
much exceeding the calibre of the mouth. For the
same reason, the rami of the lower jaw, which consist
of dentary, splenial, angular, and articular
elements, with the addition of a coronoid in the
Boidæ and a few other small families, are connected
at the symphysis by a very extensible elastic ligament.</p>

<p class='c005'>The hyoid apparatus is reduced to a pair of cartilaginous
filaments situated below the trachea, and
united in front.</p>

<p class='c005'>There are various modifications according to the
genera. A large vacuity may be present between the
frontal bones and the basisphenoid (<i>Psammophis</i>,
<span class='pagenum'><a name='Page_43' id='Page_43'>43</a></span>
<i>Cœlopeltis</i>); the maxillary may be much abbreviated
and movable vertically, as in the Viperidæ; the
pterygoids may taper and converge posteriorly,
without any connexion with the quadrate, as in the
Amblycephalidæ; the supratemporal may be much
reduced, and wedged in between the adjacent bones
of the cranium; the quadrate may be short or extremely
large; the prefrontals may join in a median
suture in front of the frontals; the dentary may be
freely movable, and detached from the articular
posteriorly.</p>

<p><a id='f04' name='f04' href='#f04'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_056.jpg' width="400" height="334"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 4</span>—<span class='sc'>Skull of</span> <i>Typhlops lumbricalis</i>. (From British Museum
Catalogue of Snakes)</p>

<p class='caption'>Lettering of the bones as in Fig. <a href='#f03'>3</a></p>
</div>

<p><span class='pagenum'><a name='Page_44' id='Page_44'>44</a></span></p>
<p><a id='f05' name='f05' href='#f05'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_057.jpg' width="400" height="380"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 5</span>—<span class='sc'>Skull of</span> <i>Glauconia macrolepis</i>. (From British Museum
Catalogue of Snakes)</p>

<p class='caption'>Lettering of the bones as in Fig. <a href='#f03'>3</a></p>
</div>

<p class='c005'>The deviation from the normal type is much
greater still when we consider the degraded, worm-like
members of the families Typhlopidæ (Fig. <a href='#f04'>4</a>,
p. <a href='#Page_43'>43</a>) and Glauconiidæ (Fig. <a href='#f05'>5</a>), in which the skull is
very compact and the maxillary much reduced. In
the former this bone is loosely attached to the lower
aspect of the cranium; in the latter it borders the
mouth, and is suturally joined to the premaxillary
and the prefrontal. In both the tranverse bone and
the supratemporal are absent, but the coronoid element
is present in the mandible.</p>

<p><span class='pagenum'><a name='Page_45' id='Page_45'>45</a></span></p>
<p><a id='f06' name='f06' href='#f06'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_058.jpg' width="400" height="248"
    alt=""/>

<p class='caption'><span class='sc'>Fig. 6</span>—<span class='sc'>Skull of</span> <i>Tropidonotus natrix</i>. (From British Museum
Catalogue of Snakes)</p>

<p class='caption'>Lettering of the bones as in Fig. <a href='#f03'>3</a></p>
</div>

<p class='c005'>The principal modifications of the skull in the
European genera may be contrasted as in the
following synopsis:</p>

<p class='c015'>I. Quadrate articulating with the cranium, supratemporal
absent; mandible much shorter than the
skull, with coronoid bone; maxillary small, on
lower aspect of cranium; pterygoids not extending
to quadrate; nasals forming long sutures with
the premaxillary, prefrontals, and frontal</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Typhlops.</i>
  </div>
</div>

<p class='c015'>II. Quadrate suspended from the supratemporal;
mandible at least as long as the skull; pterygoids
extending to quadrate or mandible.</p>

<p class='c016'>
<span class='pagenum'><a name='Page_46' id='Page_46'>46</a></span>
<i>A.</i> Mandible with coronoid bone; nasals in sutural
contact with frontals and prefrontals; transverse
bone short, not projecting much beyond
cranium; maxillary not half as long as
mandible, which is not longer than skull (to
occiput)</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Eryx.</i>
  </div>
</div>

<p><a id='f07' name='f07' href='#f07'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_059.jpg' width="400" height="368"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 7</span>—<span class='sc'>Skull of</span> <i>Zamenis gemonensis</i>. (From British Museum
Catalogue of Snakes)</p>
</div>

<p class='c016'><i>B.</i> No coronoid bone; nasals isolated.</p>

<p class='c017'>1. Maxillary elongate, not movable vertically.</p>

<p class='c025'><i>a.</i> Maxillary half as long as mandible.</p>

<p class='c015'>Supratemporal half as long as skull, projecting far
<span class='pagenum'><a name='Page_47' id='Page_47'>47</a></span>
beyond cranium; mandible much longer than
skull</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Tropidonotus.</i>
  </div>
</div>

<p class='c015'>Supratemporal not half as long as skull, projecting
far beyond cranium; mandible much longer than
skull</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Zamenis.</i>
  </div>
</div>

<p><a id='f08' name='f08' href='#f08'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_060.jpg' width="400" height="349"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 8</span>—<span class='sc'>Skull of</span> <i>Coluber longissimus</i>. (From British Museum
Catalogue of Snakes)</p>
</div>

<p class='c015'>Supratemporal not half as long as skull, projecting
but slightly beyond cranium; mandible much
longer than skull</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coluber.</i>
  </div>
</div>

<p class='c015'>Supratemporal not half as long as skull, not projecting
beyond cranium; mandible not longer than
skull</p>

<div class='nf-right-c0'>
<div class='nf-right c024'  >
    <i>Coronella</i>, <i>Contia</i>.
  </div>
</div>

<p class='c025'>
<span class='pagenum'><a name='Page_48' id='Page_48'>48</a></span>
<i>b.</i> Maxillary not half as long as mandible,
which is longer than skull; supratemporal
not half as long as skull, projecting beyond
cranium.</p>

<p><a id='f09' name='f09' href='#f09'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_061.jpg' width="400" height="356"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 9</span>—<span class='sc'>Skull of</span> <i>Coronella austriaca</i>. (From British Museum
Catalogue of Snakes)</p>
</div>

<p class='c017'>Quadrate longer than supratemporal; maxillary
much longer than quadrate, nearly straight in front
of prefrontal; a large vacuity between the frontal
bones and the basisphenoid</p>

<div class='nf-right-c0'>
<div class='nf-right c030'  >
    <i>Cœlopeltis.</i>
  </div>
</div>

<p class='c017'>Quadrate not longer than supratemporal; maxillary
little longer than quadrate, strongly curved in front
of prefrontal</p>

<div class='nf-right-c0'>
<div class='nf-right c030'  >
    <i>Macroprotodon.</i>
  </div>
</div>

<p class='c017'>
<span class='pagenum'><a name='Page_49' id='Page_49'>49</a></span>
Quadrate longer than supratemporal; maxillary
little longer than quadrate, nearly straight in front
of prefrontal</p>

<div class='nf-right-c0'>
<div class='nf-right c030'  >
    <i>Tarbophis.</i>
  </div>
</div>

<p><a id='f10' name='f10' href='#f10'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_062.jpg' width="400" height="379"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 10</span>—<span class='sc'>Skull of</span> <i>Vipera lebetina</i>. (From British Museum
Catalogue of Snakes)</p>

<p class='caption'>Lettering of the bones as in Fig. <a href='#f03'>3</a></p>
</div>

<p class='c025'>2. Maxillary much abbreviated and erectile;
supratemporal not half as long as skull;
mandible much longer than skull; basioccipital
with a strong process.</p>

<p class='c016'>
<span class='pagenum'><a name='Page_50' id='Page_50'>50</a></span>
Maxillary bone solid</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Vipera.</i>
  </div>
</div>

<p class='c016'>Maxillary bone hollowed out</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Ancistrodon.</i>
  </div>
</div>

<p class='c032'>The vertebræ number 130 to 500—in the European
forms 147 (<i>Vipera ursinii</i>) to 330 (<i>Coluber leopardinus</i>).</p>

<p class='c032'>The vertebral column consists of an atlas (composed
of two vertebræ) without ribs; numerous precaudal
vertebræ, all of which, except the first or first
three, bear long, movable, curved ribs with a small
posterior tubercle at the base, the last of these ribs
sometimes forked; two to ten so-called “lumbar
vertebræ” without ribs, but with bifurcate transverse
processes (lymphapophyses) enclosing the lymphatic
vessels; and a number of ribless caudal vertebræ with
simple transverse processes. When bifid, the ribs or
transverse processes have the branches regularly
superposed.</p>

<p class='c032'>The centra have the usual cup-and-ball articulation,
with the nearly hemispherical or transversely elliptic
condyle at the back (procœlous vertebræ), whilst the
neural arch is provided with additional articular surfaces
in the form of pre- and post-zygapophyses, broad,
flattened, and overlapping, and of a pair of anterior
wedge-shaped processes called zygosphene, fitting
into a pair of corresponding concavities, zygantrum,
just below the base of the neural spine. Thus the
vertebræ of snakes articulate with each other by eight
joints in addition to the cup-and-ball on the centrum,
and interlock by parts reciprocally receiving and
entering one another, like the joints called “tenon-and-mortice”
<span class='pagenum'><a name='Page_51' id='Page_51'>51</a></span>
in carpentry. The precaudal vertebræ
have a more or less high neural spine which, as a
rare exception (<i>Xenopholis</i>), may be expanded and
plate-like above, and short or moderately long transverse
processes to which the ribs are attached by a
single facet. The centra of the anterior vertebræ
emit more or less developed descending processes,
or hæmapophyses, which are sometimes continued
throughout (Fig. <a href='#f11'>11</a>, A), as in <i>Tropidonotus</i>, <i>Vipera</i>,
and <i>Ancistrodon</i>, among European genera.</p>

<p><a id='f11' name='f11' href='#f11'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_064.jpg' width="400" height="240"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 11</span>—<span class='sc'>Posterior Precaudal Vertebræ of</span> <i>Lioheterodon</i> (A) <span class='sc'>AND</span>
<i>Heterodon</i> (B). (From British Museum Catalogue of Snakes)
</p>

<p class='caption'><i>a</i>, Back view; <i>b</i>, lower view; <i>c</i>, side view.</p>
</div>

<p class='c032'>In the caudal region, elongate transverse processes
take the place of ribs, and the hæmapophyses are
paired, one on each side of the hæmal canal. In the
Rattlesnakes the seven or eight last vertebræ are
enlarged and fused into one.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_52' id='Page_52'>52</a></span>
No snake shows any rudiments of the pectoral
arch, but remains of the pelvic are found in the
<i>Typhlopidæ</i>, the <i>Glauconiidæ</i>, the <i>Boidæ</i>, and the
<i>Ilysiidæ</i>. In the first these vestiges are reduced to a
single bone (ilium?) on each side; in the second they
consist of ilium, pubis, and ischium, the latter forming
a ventral symphysis, and a rudimentary femur;
whilst in the third there is a long ilium, attached to
the lower branch of the first bifurcate transverse process
of the lumbar vertebræ, bearing three short
bones, the longest of which, regarded as the femur,
terminates in a claw-like spur which, in males at
least, usually appears externally on each side of the
vent.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_53' id='Page_53'>53</a></span>
  <h2 id='ch05' class='c003'>CHAPTER V<br /> <br />DENTITION</h2>
</div>
<p class='drop-capa c033'    >In the most generalized snakes—those which
show the nearest approach to lizards—teeth are
present not only on the rami of both jaws, but also
on the premaxillary bone, on the palatines, and on
the pterygoids. A reduction of the dentition takes
place in various genera, in which the teeth of either
the upper or the lower jaw, and of the palatines or
pterygoids, or both, may be absent, and the premaxillary
is devoid of teeth in the great majority,
including all European representatives, of the Ophidia.</p>

<p class='c032'>In the egg-eating snakes of the genera <i>Dasypeltis</i>
and <i>Elachistodon</i> the dentition is very much reduced,
in accordance with the peculiar régime, and this
deficiency is compensated by the development on
some of the anterior thoracic vertebræ of long, tooth-like
processes (hypapophyses) directed forwards, and
capped with a remarkably dense, vitreous tissue
simulating enamel, the function of these tooth-like
processes being to break the shell of the egg within
the gullet, where none of its contents are lost, the
shell being afterwards rejected through the mouth in
the form of a pellet.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_54' id='Page_54'>54</a></span>
With the exception of the worm-like Typhlopidæ,
which are provided with a few teeth in the upper jaw
only, European snakes have teeth on the maxillary,
palatine, pterygoid, and dentary bones. Unless the
maxillary be strongly abbreviated and modified in
connexion with the poison apparatus, as in the
Viperidæ, the teeth in the jaws as well as on the
palate form single longitudinal series; they are
elongate, conical, with or without a sharp posterior
edge, more or less recurved, acutely pointed, sometimes
needle-like, and directed backwards, as behoves
their function, which, in addition to attack and
defence, is to prevent the retrogression of the prey
in the act of prehension and deglutition. A notable
exception occurs in the genus <i>Iguanognathus</i>, from
Sumatra, all the teeth having spatulate crowns
ribbed along the outer side. Unfortunately, nothing
is known as to the food of this remarkable snake.
The teeth are coated with a thin layer of enamel. It
was held, for a time, that the glossy outer coating was
only due to a denser structure of the dentine. As in
all living Reptiles with the exception of the Crocodiles,
the teeth are not implanted in true sockets, but
simply ankylosed to the bone on which, when detached,
their slightly enlarged base, or rather the
bony tissue on which it rests, leaves a shallow impression,
or pseudo-socket. In the process of biting
or feeding, some of the teeth are frequently lost, and
are readily replaced by others lying in reserve in the
<span class='pagenum'><a name='Page_55' id='Page_55'>55</a></span>
gum at the inner side, and becoming fixed to the bone
soon after a vacancy occurs. Such replacement teeth,
of different grades of development, form several series,
so that in a snake like our common <i>Tropidonotus</i> the
mouth may contain four times as many teeth as are
functional, without reckoning different earlier stages
of tooth germs which escape ordinary observation,
being placed vertically one above the other.</p>

<p class='c032'>Three types of teeth, connected by every intermediate
step, are distinguished: the solid, the
grooved, and the canaliculated or tubular, so-called
“perforated”; the third, as we shall explain, being
only a further modification of the second. In the
grooved tooth, a sulcus runs along the anterior or
outer surface, its object being to convey into the
wound the secretion of a poison gland. It varies in
depth according to the species, and may be so slight
as to escape detection without a very strong magnifying
glass. In some the sulcus may be very deep and
wide, forming a canal round which the tooth folds to
the extent of its borders nearly meeting; from this
condition the so-called “perforated” fang is derived
through the complete fusion of the borders of the
tooth, and the obliteration of the line of union except
at each extremity. The structure of such a fang may
be best understood by imagining a tooth, lined all
round with the same layer of dentine and enamel,
being flattened out in a vertical plane and then
folded over, the outer edges coalescing on the front
<span class='pagenum'><a name='Page_56' id='Page_56'>56</a></span>
median line in such a way that the inner wall of
the tooth is in reality the anterior surface, and
the outer wall the posterior surface, of the ordinary
tooth.</p>

<p class='c032'>Grooved teeth, with open canal, are situated either
at the anterior extremity (Proteroglyphs) or at the
posterior extremity (Opisthoglyphs) of the maxillary
bone, usually followed or preceded by a series of solid
teeth, which in some cases may likewise show a
more or less distinct groove. Such may also be
present on the teeth of the lower jaw, as in the European
<i>Cœlopeltis</i>, in some specimens of which a faint
groove is visible on the outer side with the aid of a
strong lens.</p>

<p class='c032'>The tubular fangs of the Viperidæ are inserted on
the posterior extremity of the much abbreviated and
erectile maxillary bone, which bears no other teeth.
The Proteroglyphs (Cobras, Coral-snakes, Sea-snakes)
and the Solenoglyphs (Vipers, Pit-vipers, Rattlesnakes)
may be regarded as the diverging extremes in the
development of the poison apparatus, both culminating
in forms with tubular fangs, the former as derived
directly from the Aglyphs (harmless snakes),
the latter from the Opisthoglyphs, likewise evolved out
of the Aglyphs. That the insertion of the poison
fangs of the Viperidæ is really on the posterior
extremity of the maxillary bone is evident from the
condition of the bone in its recumbent position,
especially in the African Viper, <i>Causus</i>, which in
<span class='pagenum'><a name='Page_57' id='Page_57'>57</a></span>
several respects departs less markedly from the Colubrid
type than our European Vipers.</p>

<p class='c032'>The poison fangs of the Viperidæ appear to be
movable, folding in the mouth when at rest, and
erected, or even thrust forward, when ready to act.
This, however, is simply due to the mobility of the
maxillary bone, to which they are ankylosed as in
all other snakes. There are normally two equally-developed
fangs, close together and side by side, to
each maxillary, followed by several replacement fangs
loosely attached behind them, usually in two series of
four. When the two fangs are <i>in situ</i>, they of course
both function in the act of biting, although only one
is in relation with the single poison duct; often, however,
there is only one fang in position, either the
right or the left, the place of the other being indicated
by a shallow socket which will soon be filled by
one of the posterior reserve fangs moving forward and
becoming ankylosed to the bone. Snake-charmers
who extract the poison fangs of the snakes they use
for their performances have therefore to renew the
operation frequently, unless they amputate the bone
on which the fangs are inserted, an injury which the
creature does not long survive.</p>

<p class='c032'>The dentition of the snakes in which the maxillary
bone is not movable vertically falls under three
divisions: the Aglyphs, in which the teeth are all solid;
the Opisthoglyphs, in which one or more (usually
two) of the hindermost teeth are provided with a
<span class='pagenum'><a name='Page_58' id='Page_58'>58</a></span>
groove; and the Proteroglyphs, in which grooved or
canaliculated teeth are situated in front, followed or
not by solid teeth. Beyond these three principal
divisions, the dentition furnishes important characters
for the classification, although that importance has
sometimes been over-estimated. The maxillary teeth
may be equal in length (Isodonts), or the anterior the
longer (Lycodonts), or the posterior the longer, increasing
gradually in size (Coryphodonts) or abruptly,
without (Syncranterians) or with a diastema, or break,
in front of them (Diacranterians). These categories
are, however, so completely connected as to preclude
their use in taxonomy beyond helping to define
genera. The number of maxillary teeth and the
relative proportions and disposition of the mandibular
teeth also afford useful generic characters.</p>

<p class='c032'>The European genera may be arranged as follows,
according to the dentition:</p>

<p class='c016'>I. Teeth few, disposed in a transverse series in the
upper jaw only</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Typhlops.</i>
  </div>
</div>

<p class='c016'>II. Teeth in both jaws and on the palatines and
pterygoids.</p>

<p class='c017'><i>A.</i> A series of solid teeth along the maxillary; no
grooved teeth.</p>

<p class='c025'>1. Anterior maxillary and mandibular teeth
longest; 9 or 10 maxillary teeth</p>

<div class='nf-right-c0'>
<div class='nf-right c029'  >
    <i>Eryx.</i>
  </div>
</div>

<p class='c025'>2. Maxillary teeth equal, or increasing in size
posteriorly.</p>

<p class='c026'>
<span class='pagenum'><a name='Page_59' id='Page_59'>59</a></span>
<i>a.</i> Mandibular teeth 17 to 30; maxillary teeth
15 to 22.</p>

<p class='c016'>Posterior maxillary teeth longest; mandibular teeth
subequal, more than 20</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Tropidonotus.</i>
  </div>
</div>

<p class='c016'>Posterior maxillary teeth longest; mandibular teeth
not more than 20, posterior smallest</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Zamenis.</i>
  </div>
</div>

<p class='c016'>Maxillary teeth subequal; mandibular teeth 20 to 25,
posterior smallest</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Coluber.</i>
  </div>
</div>

<p class='c026'><i>b.</i> Mandibular teeth 14 or 15, subequal; maxillary
teeth 12 to 15.</p>

<p class='c016'>Maxillary teeth increasing in size</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Coronella.</i>
  </div>
</div>

<p class='c016'>Maxillary teeth subequal</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Contia.</i>
  </div>
</div>

<p class='c017'><i>B.</i> One or two enlarged grooved fangs behind the
series of solid maxillary teeth.</p>

<p class='c016'>14 to 17 subequal solid maxillary teeth, forming a
continuous series; 21 to 23 mandibular teeth,
anterior strongly enlarged</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Cœlopeltis.</i>
  </div>
</div>

<p class='c016'>9 to 11 solid maxillary teeth, fourth and fifth or fifth
and sixth enlarged, followed by an interspace;
sixth mandibular tooth fang-like, followed by an
interspace</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Macroprotodon.</i>
  </div>
</div>

<p class='c016'>9 or 10 solid maxillary teeth, forming a continuous
series, decreasing in length posteriorly; anterior
mandibular teeth strongly enlarged</p>

<div class='nf-right-c0'>
<div class='nf-right c020'  >
    <i>Tarbophis.</i>
  </div>
</div>

<p class='c017'><i>C.</i> Maxillary with only two large canaliculated
fangs side by side, one of which may be missing;
anterior mandibular teeth longest</p>

<div class='nf-right-c0'>
<div class='nf-right c030'  >
    <i>Vipera</i>, <i>Ancistrodon</i>.
  </div>
</div>

<p><span class='pagenum'><a name='Page_60' id='Page_60'>60</a></span></p>
<p><a id='f12' name='f12' href='#f12'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_073.jpg' width="250" height="345"
    alt=""/>
<p class='hi-caption'><span class='sc'>Fig. 12</span>—<span class='sc'>Maxillary and Mandible of</span>—(<i>a</i>) <i>Tarbophis fallax</i>;
(<i>b</i>) <i>Cœlopeltis monspessulana</i>; (<i>c</i>) <i>Macroprotodon cucullatus</i>. (From
British Museum Catalogue of Snakes)</p></div>

<p class='c032'>In counting the teeth for the purpose of using this
key, care must be taken to ascertain the full number,
as it frequently happens that one or more are missing;
but their place is indicated by the shallow
pits in which their base was implanted, the overlooking
of which might convey the impression of a
hiatus such as is characteristic of certain genera—<i>Macroprotodon</i>,
for instance. Needless to say, the loose
teeth which are in reserve on the inner side of the
jaws or behind the tubular fangs are not taken into
consideration, the numbers given being those of
<span class='pagenum'><a name='Page_61' id='Page_61'>61</a></span>
functional teeth only. Although as a rule the teeth
can be counted easily, on a specimen preserved in
spirit, by simply pushing aside the lips and gums
with the finger, it is sometimes necessary to remove
and clean the bones of the jaws, an operation which
does not require much skill.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_62' id='Page_62'>62</a></span>
  <h2 id='ch06' class='c003'>CHAPTER VI<br /> <br />POISON APPARATUS—DIFFERENT KINDS OF POISONS</h2>
</div>
<p class='drop-capa c033'    >The gland which secretes the poison is a modification
of the parotid salivary gland of other
Vertebrates, and is usually situated on each side of
the head below and behind the eye, invested in a
muscular sheath. It is provided with large alveoli
in which the venom is stored before being conveyed
by a duct to the base of the channelled or tubular
fang through which it is ejected.</p>

<p class='c032'>In the Vipers, which furnish examples of the
most highly developed poison apparatus, although
inferior to some in its toxic effects, the poison gland
is very large and in intimate relation with the
masseter or temporal muscle, consisting of two bands,
the superior arising from behind the eye, the inferior
extending from the gland to the mandible. When
the snake bites, the jaws close up, causing the gland
to be powerfully wrung, and the poison pressed out
into the duct. From the anterior extremity of the
gland the duct passes, below the eye and above the
maxillary bone, where it makes a bend, to the basal
orifice of the poison fang, described above (p. <a href='#Page_55'>55</a>),
<span class='pagenum'><a name='Page_63' id='Page_63'>63</a></span>
which is ensheathed in a thick fold of mucous
membrane, the <i>vagina dentis</i>. By means of the
movable maxillary bone (<i>supra</i>, p. <a href='#Page_49'>49</a>) hinged to the
prefrontal, and connected with the tranverse bone
which is pushed forward by muscles set in action by
the opening of the mouth, the tubular fang is erected
and the poison discharged through the distal orifice
in which it terminates.</p>

<p><a id='f13' name='f13' href='#f13'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_076.jpg' width="400" height="213"
    alt=""/>

<p class='caption'><span class='sc'>Fig. 13</span>—<span class='sc'>Poison Apparatus of Rattlesnake: Venom Gland
and Muscles (Lateral View).</span> (After Duvernoy)</p>

<p class='hi-caption'><i>a</i>, Venom gland; <i>a´</i>, venom duct; <i>b</i>, anterior temporal muscle;
<i>b´</i>, mandibular portion of same; <i>c</i>, posterior temporal muscle;
<i>d</i>, digastricus muscle; <i>e</i>, posterior ligament of gland; <i>f</i>, sheath
of fang; <i>g</i>, middle temporal muscle; <i>h</i>, external pterygoid
muscle; <i>i</i>, maxillary salivary gland; <i>j</i>, mandibulary salivary
gland.</p>
</div>

<p class='c032'>In some of the Proteroglyphous Colubrids, as we
have seen, the poison fangs are not tubular, but only
channelled and open along the anterior surface; and
as the maxillary bone in these snakes is more or less
elongate, and not or but slightly movable vertically,
<span class='pagenum'><a name='Page_64' id='Page_64'>64</a></span>
the poison duct runs above the latter, making a bend
only at its anterior extremity, and the tranverse bone
has not the same action on the erection of the fangs.
Otherwise the mechanism is the same.</p>

<p class='c032'>In the Opisthoglyphous Colubrids, with grooved
teeth situated at the posterior extremity of the
maxilla, a small posterior portion of the upper
labial or salivary gland is converted into a poison-secreting
organ, distinguished by a light yellow
colour, provided with a duct larger than any of
those of the labial gland, and proceeding inward
and downward to the base of the grooved fang; the
duct is not in direct connexion with the groove, but
the two communicate through the mediation of the
cavity enclosed by the folds of mucous membrane
surrounding the tooth, and united in front.</p>

<p class='c032'>The reserve or successional teeth, which are
always present just behind or on the side of the
functional fang of all venomous snakes, are in no
way connected with the duct until called upon to
replace a fang that has been lost. It could not be
otherwise, since the duct would require a new
terminal portion for each new fang; and as the
replacement takes place alternately from two parallel
series, the new poison-conveying tooth does not
occupy exactly the same position as its predecessor.</p>

<p class='c032'>Two genera, <i>Doliophis</i> among the Elapine Colubrids,
and <i>Causus</i> among the Viperids, are highly
remarkable for having the poison gland and its duct
<span class='pagenum'><a name='Page_65' id='Page_65'>65</a></span>
of a great length, extending along each side of the
body and terminating in front of the heart. Instead
of the muscles of the temporal region serving to
press out the poison into the duct, this action is
performed by those of the side of the body.</p>

<p class='c032'>When biting, a Viperid snake merely strikes, discharging
the venom the moment the fangs penetrate
the skin, and then immediately leaves go. A Proteroglyph
or Opisthoglyph, on the contrary, closes
its jaws like a dog on the part bitten, often holding
on firmly for a considerable time.</p>

<p class='c032'>The poison, which is mostly a clear limpid fluid of
a pale straw or amber colour, more rarely greenish,
sometimes with a certain amount of suspended
matter, is exhausted after several bites, and the
glands have to recuperate.</p>

<p class='c032'>It must be added that the poison can be ejected
otherwise than by a bite, as in the so-called Spitting
Snakes of the genera <i>Naia</i> and <i>Sepedon</i>. The fact
that some of these deadly snakes when irritated are
in the habit of shooting poison from the mouth, at a
distance of 4 to 8 feet, even apparently aiming
at a man’s face, has been too often witnessed in
India and Malaya, and especially in Africa, from the
days of the ancient Egyptians, for any doubt to
subsist as to their being endowed with this faculty,
but the mechanism by which this action is produced
has not been satisfactorily explained. In all probability,
the poison escapes from the sheath of
<span class='pagenum'><a name='Page_66' id='Page_66'>66</a></span>
mucous membrane surrounding the base of the
fangs, and is mixed with ordinary saliva, the membranes
of the mouth perhaps acting as lips, in which
case the term “spitting” would not be incorrect. The
spitting, which may take place three or four times
in succession, has been observed to be preceded by
some chewing movements of the jaws. If reaching
the eye, the poisonous fluid causes severe inflammation
of the cornea and conjunctiva, but no more
serious results if washed away at once.</p>

<p class='c032'>Snake poisons is a subject which has always
attracted much attention, and which has made great
progress within the last quarter of a century, especially
as regards the defensive reaction by which
the blood may be rendered proof against their effect
by processes similar to vaccination—antipoisonous
serotherapy. The studies to which we allude have
not only conduced to a method of treatment against
snake-bites, but have thrown a new light on the
great problem of immunity. They have shown that
the antitoxic serums do not act as chemical antidotes
in destroying the venom, but as physiological antidotes;
that, in addition to the poison glands, snakes
possess other glands supplying their blood with
substances antagonistic to the poison, such as also
exist in various animals refractory to snake poison,
the hedgehog and the mungoose for instance.
Unfortunately, the specificity of the different snake
poisons is such that, even when the physiological
<span class='pagenum'><a name='Page_67' id='Page_67'>67</a></span>
action appears identical, serum injections or graduated
direct inoculations confer immunity towards
one species or a few allied species only. Thus, a
European in Australia who had become immune
to the poison of the deadly <i>Notechis scutatus</i>,
manipulating these snakes with impunity, and
was under the impression that his immunity extended
also to other species, when bitten by a
<i>Denisonia superba</i>, an allied Elapine, died the following
day. In India, the serum prepared with the
venom of <i>Naia tripudians</i> has been found to be
without effect on the poison of <i>Naia bungarus</i>, the
two species of <i>Bungarus</i>, and the Vipers <i>Vipera
russelli</i>, <i>Echis carinatus</i>, and <i>Lachesis gramineus</i>.
<i>Vipera russelli</i> serum is without effect on Colubrine
venoms, and on those of <i>Echis</i> and <i>Lachesis</i>. In
Brazil, serum prepared with the venom of <i>Lachesis
lanceolatus</i> has proved to be without action on
<i>Crotalus</i> poison. These examples, and others which
could be given, show that the hopes which were
at first entertained as to the benefits to be conferred
on mankind by the serum treatment were somewhat
over-sanguine—at least as regards countries like
India, where, different kinds of poisonous snakes
occurring together, it is sometimes impossible to
know by which the bite has been inflicted.</p>

<p class='c032'>Chemistry teaches that snake venoms consist for
the most part of solutions of modified proteids, and
all attempts to separate the toxic principles from
<span class='pagenum'><a name='Page_68' id='Page_68'>68</a></span>
such proteids have hitherto been unsuccessful.
Accordingly, at the present time we must regard
such toxic principles as residing in some special
grouping of a portion of the atoms in the complex
venom proteid molecule. The analysis of their
physiological actions has proved them to be made
up of a great many more constituents than would be
imagined from their chemical composition.</p>

<p class='c032'>The effect of the poison of Proteroglyphous
Colubrids (Hydrophids, Cobras, <i>Bungarus</i>, <i>Elaps</i>,
<i>Pseudechis</i>, <i>Notechis</i>, <i>Acanthophis</i>) is mainly on the
nervous system, respiratory paralysis being quickly
produced by bringing the poison into contact with
the central nervous mechanism which controls
respiration; the pain and local swelling which
follow a bite are not usually severe.</p>

<p class='c032'>Viper poison (<i>Vipera</i>, <i>Echis</i>, <i>Lachesis</i>, <i>Crotalus</i>)
acts more on the vascular system, bringing about
coagulation of the blood and clotting of the
pulmonary arteries; its action on the nervous
system is not great, no individual group of nerve cells
appears to be picked out, and the effect upon respiration
is not so direct; the influence upon the circulation
explains the great depression which is a symptom
of Viperine poisoning. The pain of the wound is
severe, and is speedily followed by swelling and discoloration.
The symptoms produced by the bite of
the European Vipers are thus described by the best
authorities on snake poison (Martin and Lamb):
<span class='pagenum'><a name='Page_69' id='Page_69'>69</a></span>
The bite is immediately followed by local pain of a
burning character; the limb soon swells and becomes
discoloured, and within one to three hours great
prostration, accompanied by vomiting, and often
diarrhœa, sets in. Cold, clammy perspiration is
usual. The pulse becomes extremely feeble, and
slight dyspnœa and restlessness may be seen. In
severe cases, which occur mostly in children, the
pulse may become imperceptible and the extremities
cold; the patient may pass into coma. In from
twelve to twenty-four hours these severe constitutional
symptoms usually pass off; but in the meantime
the swelling and discoloration have spread
enormously. The limb becomes phlegmonous, and
occasionally suppurates. Within a few days recovery
usually occurs somewhat suddenly, but death may
result from the severe depression or from the
secondary effects of suppuration. That cases of
death, in adults as well as in children, are not
infrequent in some parts of the Continent is
mentioned in the last chapter of this Introduction.</p>

<p class='c032'>The bite of all the Proteroglyphous Colubrids,
even of the smallest and gentlest, such as the <i>Elaps</i>
or Coral-snakes, is, so far as known, deadly to man.
The Viperidæ differ much among themselves in the
toxicity of their venom. Some, such as the Indian
<i>Vipera russelli</i> and <i>Echis carinatus</i>, the American
<i>Ancistrodon</i>, <i>Crotalus</i>, <i>Lachesis mutus</i> and <i>lanceolatus</i>,
the African <i>Causus</i>, <i>Bitis</i>, and <i>Cerastes</i>, cause fatal
<span class='pagenum'><a name='Page_70' id='Page_70'>70</a></span>
results unless a remedy be speedily applied. On the
other hand, the Indian and Malay <i>Lachesis</i> seldom
cause the death of man, their bite in some instances
being no worse than the sting of a hornet. The
bite of the larger European Vipers may be very
dangerous, and followed by fatal results, especially
in children, at least in the hotter parts of the
Continent; whilst the small <i>Vipera ursinii</i>, which
hardly ever bites unless roughly handled, does not
seem to be possessed of a very virulent poison, and,
although very common in some parts of Austria-Hungary,
is not known to have ever caused a serious
accident.</p>

<p class='c032'>It is noteworthy that the size of the poison fangs
is in no relation to the virulence of the venom.
The comparatively innocent Indo-Malay <i>Lachesis</i>
alluded to above have enormous fangs, whilst the
smallest fangs are found in the most justly dreaded
of all snakes, the Hydrophids.</p>

<p class='c032'>Little is known of the physiology of the poison of
the Opisthoglyphous Colubrids, except that in most
cases it approximates to that of the Proteroglyphs.
Experiments on <i>Cœlopeltis</i>, <i>Psammophis</i>, <i>Trimerorhinus</i>,
<i>Dipsadomorphus</i>, <i>Trimorphodon</i>, <i>Dryophis</i>,
<i>Tarbophis</i>, <i>Hypsirhina</i>, and <i>Cerberus</i>, have shown
these snakes to be possessed of a specific poison,
small mammals, lizards, or fish, being rapidly
paralyzed and succumbing in a very short time,
whilst others (<i>Eteirodipsas</i>, <i>Ithycyphus</i>) do not seem
<span class='pagenum'><a name='Page_71' id='Page_71'>71</a></span>
to be appreciably venomous. Man, it is true, is not
easily affected by the bite of these snakes, since, at
least in most of those which have a long maxillary
bone, the grooved fangs are placed too far back to
inflict a wound under ordinary circumstances. There
are, however, exceptions. A case was reported a
few years ago of a man in South Africa nearly dying
as a result of the bite of the Boomslang, <i>Dispholidus
typus</i>, the symptoms, carefully recorded, being those
characteristic of Viperine poisoning, an important
fact to oppose to the conclusions, based on the
physiological experiments on <i>Cœlopeltis</i>, which
appeared to disprove the theory that the Viperidæ
may have been derived from Opisthoglyphous
Colubrids.</p>

<p class='c032'>Experiments made with the secretion of the
parotid gland of <i>Tropidonotus</i> and <i>Zamenis</i> have
shown that even Aglyphous snakes are not entirely
devoid of venom, and point to the conclusion that
the physiological difference between so-called harmless
and poisonous snakes is only one of degree, just
as there are various steps in the transformation of an
ordinary parotid gland into a poison gland or of a
solid tooth into a tubular fang.</p>

<p class='c032'>The question whether all snakes are immune to
their own poison is not yet definitely settled. Most
snakes certainly are, and it is a remarkable fact that
certain harmless species, such as the North American
<i>Coronella getula</i> and the Brazilian <i>Rhachidelus brazili</i>,
<span class='pagenum'><a name='Page_72' id='Page_72'>72</a></span>
are proof against the poison of the Crotalines which
frequent the same districts, and which they are able
to overpower and feed upon. The Cribo, <i>Spilotes
variabilis</i>, is the enemy of the Fer-de-lance in St.
Lucia, and it is said that in their encounters the
Cribo is invariably the victor. Repeated experiments
have shown our Common Snake, <i>Tropidonotus
natrix</i>, not to be affected by the bite of <i>Vipera berus</i>
and <i>V. aspis</i>, this being due to the presence, in the
blood of the harmless snake, of toxic principles
secreted by the parotid and labial glands, and
analogous to those of the venom of these Vipers.</p>

<p class='c032'>The Hedgehog, the Mungoose, the Secretary Bird,
and a few other birds feeding on snakes, are known
to be immune to an ordinary dose of snake poison;
whether the pig may be considered so is still uncertain,
although it is well known that, owing to its
subcutaneous layer of fat, it is often bitten with
impunity. The Garden Dormouse (<i>Myoxus quercinus</i>)
has recently been added to the list of animals
refractory to Viper poison.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_73' id='Page_73'>73</a></span>
  <h2 id='ch07' class='c003'>CHAPTER VII<br /> <br />NERVOUS SYSTEM—SENSE ORGANS</h2>
</div>
<p class='drop-capa c033'    >The brain is small and of very oblong shape. It
consists of smooth cerebral hemispheres, small
optic lobes, a still smaller cerebellum, and long olfactory
lobes; the pineal body is not accompanied by a
parietal organ. The spinal accessory cranial nerve
is absent, and the sympathetic system is but feebly
developed.</p>

<p class='c032'>The eyes have been noticed above (p. <a href='#Page_12'>12</a>). When
normally developed they are susceptible of a slight
movement under the transparent disc, quite independent
from the cornea, which covers them, and from
which they are separated by the so-called “lacrymal
chamber.” There are two lacrymal glands, one in
front and one behind; the lacrymal duct opens into
the posterior nares. A sclerotic bony ring is absent.</p>

<p class='c032'>The olfactory organ proper is little developed, but
is accompanied by an accessory organ, Jacobson’s
organ, consisting of a pair of pediculate, cup-shaped
sacs, between the nasal sacs and the roof of the
mouth, encapsuled by the vomers and the turbinal
bones, lined by olfactory epithelium, and opening in
the mouth just in front of the choanæ. As this
<span class='pagenum'><a name='Page_74' id='Page_74'>74</a></span>
organ, richly provided with nerves, communicates
with the inside of the mouth, its function may be to
smell the prey as it passes through previous to deglutition.
Snakes cannot be credited with a keen
sense of smell, although undoubtedly guided by it
during the nuptial period.</p>

<p class='c032'>In the more thoroughly aquatic snakes, the nostril
may be closed, when respiration is suspended, by a
spongy tissue, which acts as a stopper, and such nostrils
are called “valvular,” although a valve is not, in
the strict sense, present; when the animal breathes,
the nostril is opened by a compression, through special
muscles, of the cavernous tissue. In some Sand-snakes
the narial opening may be reduced to a
crescentic slit.</p>

<p class='c032'>The sense of hearing is not much developed.
Tympanum, tympanic cavity, and Eustachian tubes
are absent. In the typical snakes a long columellar
rod (the stapes), with a fibrous or cartilaginous pad at
the outer end, extends from the fenestra ovalis in the
cranium to the quadrate, but in the degraded burrowing
forms the stapes is a small bony plate closing the
fenestra ovalis.</p>

<p class='c032'>With one exception (<i>Eryx jaculus</i>, which is said by
Schreiber to lap like a lizard), the tongue is not used
for drinking or for the prehension or gustation of
food, nor for hissing, but is a tactile organ protruded
on any object the snake wishes to probe. It is slender
and deeply bifid at the end, smooth, very protractile,
<span class='pagenum'><a name='Page_75' id='Page_75'>75</a></span>
often quite to the length of the head, and furnished
with many sensory corpuscules. It is darted and
vibrated on the least excitement, and is usually looked
upon by the ignorant as a “sting.” In most snakes
it is much pigmented, dark brown or black; in a few
it is flesh-coloured or bright red. The tongue is
entirely retractile into a sheath below the glottis and
opening in front of it; it is always withdrawn into
the sheath when the snake bites or feeds.</p>

<p class='c032'>Other organs, which, in the absence of a satisfactory
explanation of their use, have been termed “organs of
a sixth sense,” reside in the head-shields and scales of
many snakes, and in the deep pits on the sides of the
head which are characteristic of various Boidæ and
a few Colubridæ.</p>

<p class='c032'>Scales often show, near their posterior extremity,
one or two small light spots or impressions, caused
by a thinning of the epidermis, which have been
called “apical pits”; they appear to coincide with the
terminations of nerve fibres extending along the
epidermal folds of the skin. Similar organs sometimes
form series on the borders of some of the head-shields,
this being particularly noticeable in the
Typhlopidæ.</p>

<p class='c032'>The large and deep pit situated between the nostril
and the eye (loreal pit) in the Crotaline Viperidæ—whence
the name Pit-vipers, or that of “cuatro
naricas” which is bestowed on them by the Spaniards
of Mexico—is divided into two chambers: an outer
<span class='pagenum'><a name='Page_76' id='Page_76'>76</a></span>
with large external orifice, and an inner, rather more
posterior in position and occupying an excavation on
the outer face of the maxillary bone. The inner
walls of these chambers are very thin and membranous,
and form a partition separating the two, except
for the presence of a minute opening; this partition is
stretched across the hollow of the maxillary bone like
the membrane of a drum, and is supplied with blood-vessels
and nerves, the latter terminating in cells of
variable form. The use of the organ, thus situated
at the base of the poison fang, and therefore in close
proximity to the sphincter of the poison duct, is still
unknown.</p>

<p class='c032'>Several of the Boidæ, such as <i>Python</i> and <i>Corallus</i>,
have deep pits in some of the upper and lower labial
shields, or also on each side of the rostral shield;
these problematic organs are in all probability also
sensory.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_77' id='Page_77'>77</a></span>
  <h2 id='ch08' class='c003'>CHAPTER VIII<br /> <br />VISCERA</h2>
</div>
<p class='drop-capa c033'    >In most snakes there is a very marked asymmetry
of the viscera and their blood-supply, the organs
of the right side being anterior to, as well as larger
than, those of the left.</p>

<p class='c032'>The heart in most cases is situated between the
anterior seventh and the anterior fourth of the body;
it may be much farther back, beyond the anterior
third, in <i>Doliophis</i>, <i>Platurus</i>, and some Viperidæ and
Amblycephalidæ, in the middle in <i>Chersydrus</i>. It is of
rather elongate form, enclosed in a pericardium in
which it lies freely, and has a sinus venosus, two
auricles, and a single ventricle divided by a septum.
Three arteries leave the ventricle, the pulmonary and
two systemic arches. The right systemic arch gives
off the carotid artery, which in many snakes, the
common Grass-snake for instance, may branch into
two, or in others be double from its origin. The
anterior abdominal vein is single in most snakes,
double in some Boidæ, and conveys blood from the
ventral body-wall to the liver. The caudal vein is
continued as the renal portal. Veins which have
been regarded as remains of the two posterior cardinal
<span class='pagenum'><a name='Page_78' id='Page_78'>78</a></span>
of lower Vertebrates have been found in some of the
Boidæ.</p>

<p class='c032'>The bifurcate transverse processes of the vertebræ
at the limit between the body and tail enclose the
lymph-hearts, which are large and more or less
elongate, metamerically divided into several chambers,
the right often more developed than the left.
The thymus gland lies on each side of the trachea,
near the heart, and the thyroid gland is in the middle
line, close to the base of the carotid artery.</p>

<p class='c032'>The trachea is long, and the tracheal rings may be
complete in front and incomplete behind, or incomplete
throughout. The bronchus opens at once into
the more or less elongate, usually single lung, with or
without a rudiment of a second, which seems to be
constantly the left; in some snakes the lung extends
nearly to the cloacal region. In most of the Boidæ
there are two well-developed lungs, the left shorter
than the right. The lung has highly cellular walls in
front, and becomes thin-walled, smooth, or but little
vascular, behind, where it may receive its blood from
the systemic and not from the pulmonary circulation.
In the Typhlopidæ and Viperidæ, as well as in
some of the Boidæ, Colubridæ, and Amblycephalidæ,
the posterior end or the greater part of the trachea
may have its wall enlarged and provided with air cells,
resembling the normal lung, with which it is usually
continuous; this has been called the “tracheal lung,”
but, although serving as an accessory breathing organ,
<span class='pagenum'><a name='Page_79' id='Page_79'>79</a></span>
it is not a prolongation of the true lung, nor does it
represent the missing left lung, as has been believed
by some authors.</p>

<p class='c032'>The glottis has a longitudinal slit, and can be projected
forwards when the pharynx is obstructed by a
voluminous prey. An epiglottis is usually absent, or
represented by a rudiment. It is, however, present in
some large American species of <i>Coluber</i> (<i>Pityophis</i>), said
to produce, when hissing, a loud and hoarse sound
which has been compared to the bellow of the bull—hence
the popular name of Bull-snakes by which they
are known. It has also been found in a few allied
species from Mexico, for which the genus <i>Epiglottophis</i>
has been proposed. This epiglottis is a narrow, thin
flap, erect in front of the glottis; it is not hinged, and
therefore not capable of falling down to cover the
opening of the windpipe during the process of swallowing,
its function evidently being to increase the sound
produced by the escape of the air from the windpipe.</p>

<p class='c032'>The larynx is represented by two longitudinal
bands of cartilage, united by transverse bands; it is
extremely long in some snakes (<i>Leptognathus</i>).</p>

<p class='c032'>The œsophagus, which may be extremely elongate,
sometimes measuring almost one-third of the
digestive canal, passes into the tubular or sac-like
stomach, often with thickened walls, which itself
gradually or abruptly merges into the narrower intestine.
The windings of the small intestine are
connected by ligamentous tissue, and enclosed in
<span class='pagenum'><a name='Page_80' id='Page_80'>80</a></span>
a common sheath of peritoneum. In several of
the Glyphodont Water-snakes (Homalopsinæ and
Hydrophiinæ), the intestine is much convoluted; in
<i>Herpeton</i> it is even longer than the body, although
when coiled occupying only one-fourth of that length.
The rectum is sometimes very short, sometimes
rather long, and its anterior portion may have a short
cæcum; it may be divided by transverse septa, with
median or lateral perforation.</p>

<p class='c032'>In snakes which swallow hard-shelled snails, the
anterior part of the intestine has its inner wall furnished
with zigzag muscular folds producing a reticulate
appearance, followed farther down by transverse
and then longitudinal folds. In these snakes the
intestine is abruptly constricted behind the stomach,
at which point the shells are broken or crushed after
their contents have been digested; whilst in the egg-eating
snakes, in which the eggshell has to be broken
previous to its contents reaching the stomach, the
oesophagus is narrowed in front of the latter, at the
point where the tooth-like ventral processes of the
vertebræ project and pierce the wall of the œsophagus
in order to aid in this function, after which the broken
shell is rejected through the mouth.</p>

<p class='c032'>The more or less elongate, feebly-lobed kidneys are
placed in the posterior part of the body, often extending
nearly to the cloaca; the right is usually a little
longer than the left, or extends a little farther forward,
or even may commence where the other ends.
<span class='pagenum'><a name='Page_81' id='Page_81'>81</a></span>
The suprarenal bodies are narrow and elongate, placed
on the renal veins or on the vena cava inferior.</p>

<p class='c032'>The ureters leave the hind ends of the kidneys, and
open through the side-walls of the cloaca on a papilla
which in the males contains also the opening of the
vas deferens. There is no urinary bladder. The
genital organs will be mentioned in the next chapter.
The liver is usually long and narrow, measuring one-fifth
to one-fourth the length of the body, on the right
side of the alimentary canal, commencing just behind
the heart or farther back. It is exceptionally short
in <i>Chersydrus</i>. It is sometimes divided by transverse
furrows. Its posterior extremity is bilobate, and the
left lobe usually extends beyond the right, although
the reverse has been observed in some snakes. The
gall-bladder, which may be absent, is remarkable for
its distance from the liver. The pancreas, elongate
but comparatively small, is located near the spleen, on
the left side of the alimentary canal, at a considerable
distance from the liver.</p>

<p class='c032'>The peritoneal part of the body-cavity is subdivided
into a number of spaces or cœlomic compartments
enclosed in serous capsules—viz., a posterior or intestino-genital,
a gastric on the left side, and a pair
round the liver, corresponding to its two lobes.</p>

<p class='c032'>Fat-bodies are much developed, either in the form
of small separate lobes, or as a continuous, much
folded band, on each side of the body.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_82' id='Page_82'>82</a></span>
  <h2 id='ch09' class='c003'>CHAPTER IX<br /> <br />ORGANS OF REPRODUCTION; PAIRING; OVIPOSITION; DEVELOPMENT</h2>
</div>
<p class='drop-capa c033'    >The genital glands are situated anterior to the
kidneys, the right extending farther forward
and often larger than the left. The testes are
elongate. The vas deferens is closely folded proximally,
and runs along the outer side of the kidney
into the cloaca close to the ureter. The ovaries are
elongate, and consist of two lamellæ, with a lymph-space
between them. The oviduct extends from
near the anterior extremity of the ovary to a common
chamber, or vagina, which is above the rectum and
opens into the cloaca; this vaginal chamber may be
more or less completely divided into two.</p>

<p class='c032'>The males are provided with a pair of intromittent
organs, or hemipenes, each connected with one of
the caudal vertebræ by a muscle (<i>retractor penis</i>) which
often exceeds it in length. These organs are cylindrical
or club-shaped and hollow, with the inner
surface divided into numerous cavities and beset
with papillæ, and usually also with hard spines, of
which those towards the apex may be greatly developed,
folded against the walls, and directed
towards the extremity. Such spines are absent in
<span class='pagenum'><a name='Page_83' id='Page_83'>83</a></span>
the snakes provided with claw-like rudiments of
hind limbs. The cavities of the hemipenis are
connected by a branch with the dorsal artery, and
it is by a flow of blood into them that erection of
the organ is accomplished. Each hemipenis is
lodged in a cavity on each side of the base of the
tail; when protruded it turns inside out, and the
inner surface becomes the outer, the papillæ and
erected spines serving to maintain a firm hold
in the vagina, from which the organ cannot be
withdrawn except by invagination. It has been
observed that the presence of spines on the hemipenis
is associated with much tougher vaginal
walls. The organ is grooved along its entire
length, the groove being the <i>sulcus spermaticus</i>,
which, when the edges of the two hemipenes meet,
forms with its fellow a canal to convey the semen
into the oviduct; this sulcus may be bifurcate, as in
the Viperids and some Colubrids.</p>

<p class='c032'>Anal pockets, secretory organs on each side of the
vent and lodged in the base of the tail, seem, in
females, to be the homologues of the hemipenes;
but this view cannot be held, since the same organs
are present, though smaller, in males also, situated
dorsally to the hemipenes. The glands with which
they are provided produce the strong and offensive
odour which appears to be a means of defence in
our Grass-snake and other species, and which also
serves to bring the sexes together, the glands being
<span class='pagenum'><a name='Page_84' id='Page_84'>84</a></span>
more active during the breeding season. A Viper-catcher
in France is said to obtain good results by
rubbing his boots with these glands, as a means of
attracting the snakes in the spring.</p>

<p class='c032'>In European species pairing takes place in spring,
sometimes again at the end of summer or in
autumn. After hibernation the testes of the males
are rather voluminous, and the sperm-ducts are often
full of spermatozoa. The male gets alongside the
female, sometimes seizing her round the neck with
his jaws, and remains stretched out against her or
twists the posterior part of his body in a few coils
around hers. In the Vipers the bodies of the pairing
individuals are completely entwined. The male
then endeavours to bring the two anal orifices
together, and when he has succeeded in getting the
female to distend her cloacal opening, the intromittent
organs are suddenly everted into the vagina.
The union of the sexes sometimes lasts only a few
minutes, but usually an hour or more; it has even
been observed to last a whole day. Several copulations
may take place at intervals of a few days.
Many snakes are gregarious during the breeding
season, and great numbers of males have been seen
wriggling round the females, forming with their
coils huge lumps or an entangled mass like a ball.
The more or less prehensile tail with which
thoroughly aquatic snakes, such as <i>Hydrophis</i> and
<i>Acrochordus</i>, are provided, is no doubt of use in
<span class='pagenum'><a name='Page_85' id='Page_85'>85</a></span>
facilitating the pairing, when it has to take place
in the water. Our European Water-snakes pair on
land.</p>

<p class='c032'>During the rutting season a slight pressure on the
base of the male’s tail may cause the protrusion of
the hemipenes, and so may a violent blow on the
spine of the reptile. Thus, recently killed specimens
of our Adder, with the organs everted, have more
than once been taken by the ignorant for snakes
with hind limbs, a mistake which must be pardoned
when we remember that male embryos of the slow-worm
and of snakes, in which the hemipenes are
normally everted, have been described by zoologists,
who should have known better, as examples showing
external vestiges of limbs.</p>

<p class='c032'>The spermatozoa soon make their way up the
oviducts, in which the ripe ova have previously
descended, or which gradually descend shortly after,
these ducts becoming dilated in consequence. There
are usually more eggs in the right than in the left
oviduct, although the reverse has occasionally been
observed.</p>

<p class='c032'>Some snakes lay eggs shortly after impregnation,
or a few weeks later; in others the young undergo
their development within the oviducts, each enveloped
in a thin, transparent, membranous capsule,
which is torn immediately before or immediately
after parturition, such species being termed “ovoviviparous.”
Just before oviposition the female curves
<span class='pagenum'><a name='Page_86' id='Page_86'>86</a></span>
the base of the tail upwards, in order to extend the
cloacal opening. The eggs are all produced together,
usually at intervals of a few minutes, and generally
adhere to one another by means of a sticky fluid
secreted by the oviducts, thus forming a clump.
In ovoviviparous snakes the young are born in
succession, in the course of a few hours or of a few
days. In many oviparous species it is the rule for
freshly-laid eggs to contain more or less developed
embryos, and <i>Coronella punctata</i> is said to produce
thin-shelled eggs which hatch in less than half the
time required for the eggs of its American congeners
under the most favourable circumstances. There is
thus almost every degree between oviparity and
ovoviviparity.</p>

<p class='c032'>These two modes of parturition bear no relation to
the natural affinities of snakes. Thus, the European
<i>Coronella austriaca</i> is ovoviviparous, and its North
American congeners are oviparous; whilst, curiously,
it is the inverse in the genus <i>Tropidonotus</i>. It was long
believed to be an invariable rule for the Viperidæ to
bring forth live young, the name Viper being derived
from this well-known peculiarity, but it has now been
ascertained that the South American <i>Lachesis mutus</i>,
the Indo-Malay <i>Lachesis monticola</i>, and the African
<i>Causus</i> and <i>Atractaspis</i>, lay eggs. All exclusively
aquatic snakes, such as the Hydrophiinæ, are ovoviviparous,
and thus dispensed from going on land for
parturition.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_87' id='Page_87'>87</a></span>
The yolk entirely fills the eggshell; there is no
albumen, or, if any exists, it is so much reduced as to
easily escape observation. The eggshell in oviparous
species contains a small amount of lime, and is
not hard, but tough and parchment-like, white or
yellowish; it is usually smooth, but in Pythons its
surface is studded with minute pores, and in the
American <i>Zamenis constrictor</i> it is rough, as if
sprinkled over with loose grains of salt. The shape
varies from a short oval to a long ellipse. It has
been observed in some snakes that the eggs, on
leaving the cloaca, are of an elongate shape, suggestive
of a short cigar, and immediately after assume
a more oval form. After they have been laid, the
eggs absorb moisture and thus increase in size, especially
in width; eggs which are at first twice as long
as broad may be almost globular just before the birth
of the young.</p>

<p class='c032'>The number of eggs or young of one brood varies
much according to the species, and also according to
the age of the mother, large females usually producing
a higher number and of a larger size than smaller
specimens of the same species. Our European
<i>Zamenis</i>, <i>Coluber</i>, and <i>Coronella</i> produce only 2 to 15;
our <i>Tropidonotus</i>, 15 to 48; our Vipers, 3 to 22.
Among exotics we may mention, as the most prolific,
<i>Bitis nasicornis</i>, up to 47 young; <i>Tropidonotus fasciatus</i>,
<i>Abastor erythrogrammus</i>, and <i>Farancia abacura</i>, 50;
<i>Lachesis lanceolatus</i>, 60; <i>Vipera russelli</i>, 63; <i>Boa constrictor</i>,
<span class='pagenum'><a name='Page_88' id='Page_88'>88</a></span>
64; <i>Tropidonotus ordinatus</i>, 78; <i>Pseudaspis
cana</i>, 80; <i>Python molurus</i>, nearly 100 eggs.</p>

<p class='c032'>The eggs are deposited in holes without any sort
of nest, under moss or decomposing leaves, in
accumulations of saw-dust, or in manure-heaps.
In many cases it has been observed that the female
remains for some time with her eggs or young, and
in the large Pythons a sort of incubation takes place,
the female remaining coiled in a spiral over the mass
of eggs for six to eight weeks; an increase of several
degrees in her temperature at that period has been
ascertained by experiments conducted with every
possible care, a remarkable fact in the case of a
so-called “cold-blooded” animal.</p>

<p class='c032'>The numerous reports of young snakes seeking
refuge in their mother’s gullet have not been substantiated
by satisfactory scientific evidence, and,
although it is perhaps wise to say that the question
remains an open one, it may be mentioned that, in
Europe at least, trained observers who have devoted
special attention to the habits of Vipers, in districts
where these reptiles are exceedingly abundant, have
never come across an instance of the form of maternal
solicitude with which these snakes in particular have
been credited. Not a single reported case of a
female snake swallowing her young for protection
rests on satisfactory evidence.</p>

<p class='c032'>The embryo is closely coiled up in a spiral. Just
before birth it is distinguished by a large, convex
<span class='pagenum'><a name='Page_89' id='Page_89'>89</a></span>
head, with large, prominent eyes, and a comparatively
short body, the scales and ventral shields
being much shorter than later in life. The umbilicus
is situated in the posterior part of the body, from
six to ten times as far from the head as from the
vent. Long after birth the umbilical slit remains
visible, and affords a means of distinguishing very
young snakes from older examples of smaller species.
In oviparous species the embryo is provided with a
very conspicuous egg-tooth, pointing forwards and
projecting from the notch in the lower border of the
rostral shield; this egg-tooth is much reduced, and
sometimes very indistinct, in the ovoviviparous
species. The function of the egg-tooth is to cut
through the tough eggshell. This, after the young
has left it, shows one or several slits in its anterior
extremity, cut as clean as if with a sharp knife. The
egg-tooth becomes loose soon after birth, and is shed
within a few hours or a few days, sometimes even
before birth in ovoviviparous species.</p>

<p class='c032'>Frequent cases have been observed of dicephalous
embryos or young, which may live for a short
time; there are even records of a three-headed snake,
stated to have been seen at Lake Ontario, and of
snakes with two heads and two tails.</p>

<p class='c032'>Unless prematurely born with a considerable mass
of vitellus attached to the umbilicus, the young
immediately after birth resent all interference, hissing,
snapping, or puffing themselves up, after the
<span class='pagenum'><a name='Page_90' id='Page_90'>90</a></span>
manner of their parents. The first shedding of the
outer coating of the epidermis follows soon after
birth; not before then does the young take to food.</p>

<p class='c032'>No snake appears to be able to breed before it is
four years old.</p>

<p class='c032'>Well-authenticated instances of different species
interbreeding are unknown, but specimens intermediate
between <i>Vipera berus</i> and <i>V. aspis</i>, and
between <i>V. berus</i> and <i>V. ammodytes</i>, have been
assumed, with much probability, to be hybrids.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_91' id='Page_91'>91</a></span>
  <h2 id='ch10' class='c003'>CHAPTER X<br /> <br />HABITS</h2>
</div>
<p class='drop-capa c033'    >Snakes may be grouped, according to their
mode of life, in five principal categories,
gradually merging into each other, or two of them
not infrequently found combined in one and the
same species. These categories are:—Ground-snakes,
Sand-snakes, Burrowing-snakes, Tree-snakes, and
Water-snakes.</p>

<p class='c032'>Ground-snakes may be defined as living above
ground, and only occasionally climbing bushes or
entering the water. Among European genera,
<i>Coronella</i> and <i>Vipera</i> are perfect examples of this
type, whilst <i>Coluber</i> and <i>Zamenis</i> approach the
Tree-snakes in often ascending bushes, or even
trees.</p>

<p class='c032'>Sand-snakes are adapted for living on loose
sand, in which they seek concealment. Such are
<i>Lytorhynchus</i> and some <i>Psammophis</i> among the
Colubridæ, <i>Cerastes</i> among the Viperidæ. <i>Eryx</i> connects
this category with the next.</p>

<p class='c032'>Burrowing-snakes live chiefly underground, and
often have the visual organ atrophied in consequence,
as in <i>Typhlops</i>; all the Typhlopidæ, Glauconiidæ,
<span class='pagenum'><a name='Page_92' id='Page_92'>92</a></span>
and Uropeltidæ, belong to this category; the Viperid
<i>Atractaspis</i> is also a burrowing type.</p>

<p class='c032'>Tree-snakes spend the greater part of their life on
bushes or trees. <i>Corallus</i> among the Boidæ, <i>Dendrophis</i>
and <i>Dendraspis</i> among the Colubridæ, <i>Atheris</i>
and various species of <i>Lachesis</i> among the Viperidæ,
may be quoted as examples.</p>

<p class='c032'>Of Water-snakes, some are exclusively aquatic,
like the marine Hydrophiinæ and the typical
Acrochordinæ (<i>Acrochordus</i>, <i>Chersydrus</i>) and Homalopsinæ
(<i>Hipistes</i>, <i>Herpeton</i>). <i>Chersydrus</i> and <i>Hipistes</i>
occur in the sea as well as in fresh water. Many
species of <i>Tropidonotus</i> (<i>T. tessellatus</i> and <i>T. viperinus</i>
in Europe), as well as the genera <i>Helicops</i>, <i>Grayia</i>,
<i>Boulengerina</i>, etc., among the Colubridæ, <i>Eunectes</i>
among the Boidæ, <i>Ancistrodon piscivorus</i> among the
Viperidæ, are chiefly but not exclusively aquatic.</p>

<p class='c032'>Our <i>Tropidonotus natrix</i> stands between the
Ground-snakes and the Water-snakes; Boas and
Pythons are as much Water-snakes as Tree-snakes.
As shown by these and many other examples which
might be given, a division into categories cannot
always be applied with precision, nor does it convey
an expression of the natural relationships of the
species, as was believed by many systematists of the
last century, who appealed to such adaptations for
the definition of families.</p>

<p class='c032'>A vertical pupil denotes more or less nocturnal
habits. Nevertheless our European Vipers, which
<span class='pagenum'><a name='Page_93' id='Page_93'>93</a></span>
are provided with such a contractile pupil, are far
from exclusively nocturnal, delighting to bask in the
sun, and pairing and feeding in the day-time. The
Boidæ appear to be more nocturnal, but no snake is
known to be absolutely so, and the two species of
<i>Coluber</i> which have been found living in perfect
darkness in limestone caves in the Malay Peninsula
and China, where they feed chiefly on bats, occur
also outside the caves, and probably never breed in
them.</p>

<p class='c032'>It is often stated in books that the organs of
locomotion for the exceedingly elongate body of
snakes are the ribs, and these creatures have even
been compared to Centipedes. This statement is no
doubt true to a certain extent for slow locomotion
on uneven ground, when the ribs and the corresponding
ventral shields afford a point of support;
but it does not account for the rapid movements, as
when a snake darts like an arrow in pursuit of its
prey or to escape from an enemy. Besides, the
winding motions are not different from those of a
Slow-worm or Glass-snake, in which, encased as they
are in a bony armour, the ribs cannot come into
play at all. The action of the muscles alone is quite
sufficient to account for the reptation of snakes,
without the ribs having to play an essential part.</p>

<p class='c032'>Not only the Cobras, but several harmless snakes,
are able to raise the anterior third of the body
vertically, when taking up a threatening attitude in
<span class='pagenum'><a name='Page_94' id='Page_94'>94</a></span>
the presence of an enemy, at the same time widening
or inflating the region behind the head.</p>

<p class='c032'>Most snakes can climb, and in this case the ribs
and ventral shields are of great assistance. The Tree-snakes,
usually characterized by a very slender, sometimes
compressed, body, or by a prehensile tail, are
specially adapted for twining themselves round
branches, and in several of them the presence of a keel
on each side of the ventral and subcaudal shields,
accompanied by a notch corresponding to the keel,
affords an additional help for climbing on vertical uneven
surfaces, such as the trunks of trees. This condition
of the ventral shields has a bearing on the
extraordinary mode of locomotion with which some
Tree-snakes (<i>Chrysopelea</i>, and probably also <i>Dendrophis</i>)
have long been credited by the Malays. We allude
to the so-called Flying-snakes, remarkable for their
habit of shooting down from trees and descending to
the ground at an oblique angle, the body being kept
rigid the whole time of the “flight.” It has been
observed in <i>Chrysopelea</i> that the ventral surface
between the lateral keels, which may be compared
to hinges, can be drawn in and become deeply
concave, whilst at the same time a slight dorso-ventral
flattening of the body takes place. During
this muscular contraction the snake is like a piece of
bamboo bisected longitudinally, and is buoyed up in
such a way as to explain its parachute-like descent.</p>

<p class='c032'>All snakes are able to swim, and the more aquatic
<span class='pagenum'><a name='Page_95' id='Page_95'>95</a></span>
kinds may spend a few hours under the water. A
<i>Python molurus</i> is known to have remained alive in a
basket sunk for thirty-six hours in a river. The best
adapted for aquatic life are the Hydrophiinæ, or Sea-snakes,
most of which never leave the water, and
are quite helpless and soon die when brought on
shore; their body is more or less compressed
posteriorly, and the tail oar-shaped. Sea-weeds and
barnacles sometimes settle on them. Algæ have also
been observed growing on the fresh-water snake
<i>Herpeton tentaculatum</i>.</p>

<p class='c032'>As regards food, Burrowing-snakes, as well as a
few small Ground-snakes, subsist mostly on worms,
insects, and myriopods; Tree-snakes on lizards,
frogs, birds and their eggs; Water-snakes on fishes
and batrachians. Among the other types, some
show a predilection for mammals, others for lizards
or snakes, whilst not a few feed indiscriminately
upon mammals, birds, reptiles and batrachians, even
on slugs, insects, and worms, in addition. However
surprising, it is a fact that spiny mammals are
occasionally eaten, spines of the Madagascar Hedgehog
(<i>Ericulus</i>) having been found in the excrements
of a <i>Boa madagascariensis</i>. Even hard-shelled eggs
and molluscs may constitute the principal or
exclusive food of certain snakes.</p>

<p class='c032'>Thus, <i>Dasypeltis</i> eats nothing but birds’ eggs, the
shells of which are crushed in the gullet, by a special
contrivance mentioned above (p. <a href='#Page_80'>80</a>), and are soon
<span class='pagenum'><a name='Page_96' id='Page_96'>96</a></span>
after rejected through the mouth as a pellet. Other
snakes, such as <i>Coluber</i> and <i>Lioheterodon</i> show themselves
partial to eggs in addition to live prey, but
their alimentary canal does not depart from the
normal, the eggs being broken in the stomach and
the remains of the shells passed with the excrements.</p>

<p class='c032'>The Amblycephalidæ subsist almost entirely on
snails and slugs, the shells of the former being
crushed in the anterior part of the intestine after
their contents have been digested, and the débris are
rejected through the vent. A small land tortoise has
been found in the stomach of a Cobra (<i>Naia haie</i>)
from Algeria.</p>

<p class='c032'>Snakes which take large prey secure it according
to three methods: By catching it simply with the
jaws, and immediately proceeding to swallow it, as
in <i>Tropidonotus</i> and in some of the Constrictors when
dealing with small animals; by constriction, after
having seized it with the jaws, crushing it in the
coils of their body and thus killing it previous
to feeding, as in the Boidæ and <i>Coluber</i>; or by
poisoning, by a mere stroke with the fangs, the
result being awaited before the meal is begun, as in
most of the Viperidæ. Other poisonous snakes
proceed according to the first method, the use of the
venom being to reduce the struggles of the victim
and to relax its muscles. Such snakes as are in the
habit of previously killing their prey show little
reluctance to accept dead food in confinement, a
<span class='pagenum'><a name='Page_97' id='Page_97'>97</a></span>
thing which others usually refuse to do; they
may, however, be deceived by the dead animal
being agitated before them, and the system now
adopted in our Zoological Gardens, of offering all
snakes previously-killed animals, has been attended
with comparative success.</p>

<p class='c032'>Some species feed almost exclusively on other
snakes, and often manage to swallow individuals as
large as, or even a little larger than, themselves.
Examples are known of harmless snakes showing
a predilection for dangerous species, to whose poison
they are immune (see p. <a href='#Page_71'>71</a>).</p>

<p class='c032'>As a rule snakes that eat fish will also eat batrachians,
but nothing higher in the scale, although
exceptions have been reported, such as the Anaconda
feeding on mammals, birds, reptiles, and fish, and our
Grass-snake having taken mice and birds. Some that
feed chiefly on lizards and snakes will occasionally eat
also mammals, and <i>vice versa</i>, but rarely frogs. On
the other hand, European Vipers accommodate themselves
to a more varied bill of fare, being known to
feed on mammals, birds, reptiles, batrachians, insects,
and slugs, and they have even been observed to eat
voles showing signs of putrefaction.</p>

<p class='c032'>The enormous prey which some snakes are able
to swallow is quite astounding. Anacondas and
Pythons, the largest snakes, have been known to
swallow calves and good-sized antelopes with their
horns, animals which, even after being somewhat
<span class='pagenum'><a name='Page_98' id='Page_98'>98</a></span>
crushed by constriction, very much exceed the
calibre of the snake. A <i>Python molurus</i> 17 feet long
is reported on good evidence to have swallowed a
gravid Axis deer. A Grass-snake half an inch in
diameter can manage a frog or toad three times
that width, and a <i>Dasypeltis</i> of the same size a hen’s
egg. Such feats are rendered possible by the
mobility of the jaws and palato-pterygoid arch on
the cranium, and the elasticity of the ligaments by
which they are attached (see above, p. <a href='#Page_42'>42</a>), as well
as by the mobility of the ribs and the absence of
sternal apparatus, together with the great distensibility
of the skin. When a snake proceeds to
dispose of a large prey, which, if it be a mammal or
bird, is usually seized head-first, it pulls itself
forward by alternate movements of the jaws, the
maxillary and the mandibular ramus of the one side,
and then of the other, being extended anteriorly and
laterally, the snake at the same time producing an
abundant salivation which renders the prey very
slimy. Several repeated alternate movements of the
jaws bring the head of the prey to the gullet, where
the muscles and ribs come into play, and the two
sides of the jaws work no longer alternately, but
together. When once in the œsophagus, the prey
progresses with much greater facility, and usually
reaches the stomach in a few minutes, whilst the
previous process of deglutition may have lasted half
an hour. While this laborious operation is going
<span class='pagenum'><a name='Page_99' id='Page_99'>99</a></span>
on, the breathing of the snake is not impaired
owing to a remarkable contrivance: the trachea
can be protruded in such a manner as to bring its
opening outside the mouth.</p>

<p class='c032'>In cases where the victim is eaten alive, the snake
has to contend with its struggles, but retrogression is
rendered impossible by the backwardly-directed
sharp teeth with which the jaws and palate are beset.
A frog is usually caught by one of the hind limbs and
swallowed back-first, the long hind limbs stretching
forwards as they fold against the body; its struggles
are often still apparent when it has reached the
œsophagus. Snakes when caught immediately after
a meal are in the habit of disgorging their food, and
it sometimes happens that a frog or toad is thus
vomited alive. An instance is known of a naturalist
having captured a Grass-snake and put it in a linen
bag. On opening it a short time after, great was his
surprise to find the snake had escaped through a
small hole in the bag, leaving instead a living toad
too big to pass through the hole.</p>

<p class='c032'>If not of too large a size, several animals will often
be swallowed in rapid succession, after which the
gorged snake will allow its digestive organs several
days, or even weeks, of repose. A large Anaconda in
the Paris Jardin des Plantes fed only thirty-six times
in the course of seven years. Digestion is usually
rapid in the small snakes, defecation taking place
twenty-four to forty-eight hours after the feeding; it
<span class='pagenum'><a name='Page_100' id='Page_100'>100</a></span>
lasts much longer in the large Boas and Pythons.
Thus, in the above-mentioned Anaconda it has been
observed to take from nine to thirty-eight days.
Even the hardest bones of birds are decomposed by
the gastric juices, but hairs, feathers, and horny productions,
are passed with the excrements, sometimes
forming regular balls. It is in most cases possible to
tell, from an inspection of the dried fæces, what a
snake has been feeding on, hairs, feathers, beaks,
claws, epidermal horny shields, bits of tooth-enamel,
being found mixed with the chalky matter which
represents the decomposed bones. As a rule there
is but one defecation after each meal, but there are
in addition more frequent renal dejections, consisting
chiefly of uric acid.</p>

<p class='c032'>In captivity snakes show themselves capricious in
the choice of food, one individual preferring mammals,
whilst another, of the same species, will
only take birds; and many, although to all appearances
perfectly healthy, will persist in refusing all
food, and allow themselves to die of starvation—a
suicide which may require months, or even years, to
accomplish. A Rattle-snake in the menagerie of the
Jardin des Plantes in Paris has lived two years and two
months without taking any food, a <i>Python sebæ</i> nearly
two years and a half, a <i>Boa madagascariensis</i> four years
and a month. A <i>Viper aspis</i> was kept for three
years without food and without losing its vicious
temper. Specimens thus fasting do not, as a rule,
<span class='pagenum'><a name='Page_101' id='Page_101'>101</a></span>
renew their epidermis, or do so but very rarely. Our
Common Adder can very seldom be induced to feed
in captivity. Other snakes may rid themselves of all
shyness to the extent of taking food from the hand,
or show such appetite as to seize a prey immediately
on being released from the small box or bag in
which they have travelled for a considerable time.</p>

<p class='c032'>Most snakes drink, and pretty often—not by
lapping with the tongue, but by drawing in water
from the mouth and immersing the anterior part of
the head. Some are said to be fond of milk, but
there is no foundation for the belief held by peasants,
that they enter sheds with the object of sucking
milk from the cows, which would be a material impossibility;
their real purpose in visiting such places
being a search for suitable dung-heaps in which to
deposit their eggs.</p>

<p class='c032'>Snakes cannot be credited with much intelligence
or educability, nor do they display any very marked
instincts. The least stupid and most easily tamed
are the species of the genera <i>Coluber</i> and <i>Coronella</i>.
There is, however, considerable difference in this
respect between individuals of the same species.
Most snakes, when freshly caught, defend themselves
by biting, and some individuals retain their savage
temper after months of captivity; others hardly ever
bite, even if molested. The Common Grass-snake,
for instance, hisses loudly and takes up a very
threatening attitude, or even pretends to snap with
<span class='pagenum'><a name='Page_102' id='Page_102'>102</a></span>
open mouth, but very seldom bites; its principal
defensive action when caught consists in voiding a
most repulsive secretion from its anal glands, which
it evidently controls, as it ceases doing so when
accustomed to being handled. The same snake also
produces, during the spring, an oily exudation from
the skin which has the same repulsive smell.
Mr. H. N. Ridley has observed a Malay snake
allied to <i>Tropidonotus</i>, <i>Macropisthodon rhodomelas</i>, to
exude drops of a white viscid liquid from the skin of
its neck, which is flattened out like that of a Cobra
when in an attitude of defence, and he noticed that
his dog, seizing the snake to worry it, foamed at the
mouth as if he had been biting a toad.</p>

<p class='c032'>The hissing is produced by the rapid expulsion of
air from the lungs through the trachea and the notch
at the end of the mouth, which is kept shut at the
time. Snakes provided with an epiglottis (see p. <a href='#Page_79'>79</a>)
produce a much louder hissing. Other sounds are
produced by some snakes. Thus, the Indian and
African Vipers of the genera <i>Echis</i> and <i>Cerastes</i> make
a curious, prolonged, rustling noise, by rubbing the
folds of the sides of the body against one another.
This sound is produced by friction between the
serrated keels of the lateral scales, which are disposed
obliquely with their tips directed downwards
and backwards; the noise can even be repeated
after the death of the animal, by twisting the body
and thus rubbing or rasping these little saws against
<span class='pagenum'><a name='Page_103' id='Page_103'>103</a></span>
one another. The same thing probably takes place
in the African genus <i>Dasypeltis</i>, in which we find a
similar arrangement of the scales, though to a less
degree.</p>

<p class='c032'>The best known sounding apparatus is that of the
Rattlesnakes, described on p. <a href='#Page_20'>20</a>. When alarmed,
these snakes gather the body in a few coils or roll
themselves up in a spiral, with the tail erect in the
centre, and vibrating with great rapidity, whilst the
head is ready for attack. Other snakes, such as the
<i>Ancistrodon</i> and some species of <i>Coluber</i> and
<i>Zamenis</i>, when excited, vibrate the tail in the same
manner; but, being deprived of the sound-producing
apparatus, this expression of their anger does not
attract the same attention. It is from such a habit,
however, that the rattle must have been evolved and
perfected, not necessarily in a Lamarckian sense, but
through the different steps by which evolution or
creation has proceeded; <i>Natura non fecit saltus</i>, as
Linnæus well said. Many suggestions have been
made as to the use of the rattle. One of them is
that the rattling resembles the sound made by
locusts, and serves to decoy insect-eating birds;
another, that it serves to call the sexes together.
Probably it is useful to the snake as a warning to
keep off disturbers which cannot serve as food, and
thus prevents useless expenditure of venom, or even
the breaking of the fangs. At any rate, it gives expression
to the snake’s excitement, as does the voice
<span class='pagenum'><a name='Page_104' id='Page_104'>104</a></span>
in the case of many other animals, and it seems
reasonable to suppose that it may be applied to
different purposes. With the advent of man, this
means of attracting attention must tend to the more
rapid extermination of the snakes which possess it.</p>

<p class='c032'>Another curious behaviour is that of feigning death,
as observed in a harmless but vicious-looking snake,
<i>Heterodon</i>, often called Puff-adder in America. It
looks more like a Viper than a harmless snake, and
when disturbed hisses loudly and flattens out the
anterior part of the body, much as does a Cobra, and
pretends to strike, although it is one of the few
snakes that never bite man. If, however, this display
proves of no avail in frightening away the intruder,
the snake rolls on its back and opens its mouth, and
then lies for a time, which may exceed a quarter of
an hour, absolutely motionless, as if dead. As soon
as it thinks the danger over, it awakens from its
spasm and rapidly moves off. It is the opinion of
those who have most experience of this snake that
this extraordinary behaviour is not to be explained
as a convulsion or faint due to fright, but constitutes
a deliberate trick to save its life. Individuals of the
South African Ringhals (<i>Sepedon hæmachates</i>) and of
the Common Grass-snake have also been observed to
feign death.</p>

<p class='c032'>The notion that snakes fascinate their prey,
attracting it or reducing it to immobility by a
mysterious power in their glittering eyes, is pure
<span class='pagenum'><a name='Page_105' id='Page_105'>105</a></span>
fable. Animals placed in a cage with a snake evince
no particular fright, and fly away when pursued, if
not actually turning round to defend themselves.
It is even dangerous to offer a good-sized snake a
wild rat for food, as all keepers of menageries know.</p>

<p class='c032'>In cold and temperate climates snakes hibernate,
lying more or less torpid in holes or hollow trees,
sometimes assembled in numbers and coiled
together in a mass. The first thing they do in
awakening in the spring is to cast the outer coating
of the epidermis, as described above (p. <a href='#Page_20'>20</a>). Several
exuviations take place during the period of activity,
sometimes pretty regularly every month, sometimes
at very irregular intervals. A few days previous to
this operation the snake is languid and abstains from
feeding; its skin is dull and the sight impaired by
the opaque condition of the lid; a day or two before
moulting, the outer stratum of the epidermis
becomes again transparent and the eye clear,
through this stratum becoming detached from the
subjacent tissue, until it is pulled off in one piece,
by the snake rubbing itself against stones or bushes.
The first exuviation takes place very shortly after
birth.</p>

<p class='c032'>Snakes are long-lived, although the limit of duration
of life is not known in any of them. They grow
slowly, and do not appear ever to reach sexual
maturity until the fourth year, when they continue
increasing in size for a long period. A <i>Python reticulatus</i>
<span class='pagenum'><a name='Page_106' id='Page_106'>106</a></span>
and an <i>Ancistrodon piscivorus</i> are reported to
have lived twenty-one years in captivity in Paris.
The young of many snakes are very secretive, and
are not often found in the open, those that are met
with being as a rule either new-born or approaching
sexual maturity.</p>

<p class='c032'>Snakes are tenacious of life, and remarkable for
the reflex movements which take place after they
have been cut to pieces, the severed parts of the body
and tail wriggling for a considerable time, and the
head endeavouring to bite. Accounts of decapitated
Rattlesnakes turning round and striking with their
bloody stumps are probably not snake stories.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_107' id='Page_107'>107</a></span>
  <h2 id='ch11' class='c003'>CHAPTER XI<br /> <br />PARASITES</h2>
</div>
<p class='drop-capa c033'    >Like all other animals, snakes are infested with
a multitude of vegetable and animal parasites,
both external and internal. About 300 species of
Ophidian parasites have been recorded; yet our
knowledge of them is very imperfect. Although
some 2,000 species of snakes are known, parasites
have not been recorded for more than 168 species,
and in the great majority of these (102) only a single
parasite: a tick, a hæmogregarine, or some intestinal
worm. Owing to the more frequent opportunity of
dissecting them, the common menagerie snakes have
yielded better records, notwithstanding the fact that
they usually lose most of their parasites through
constant handling, prolonged fasting, and artificial
surroundings. Thus, we have a list of thirteen species
for the Indian <i>Python molurus</i>, and one of twenty-two
species for the <i>Boa constrictor</i>. But no systematic
search appears to have been attempted, save, perhaps,
in the case of a few European species.</p>

<p class='c032'>It is interesting to notice that it was the finding of
an Ophidian parasite which prompted Francesco
Redi to write his famous “Observations on the Living
<span class='pagenum'><a name='Page_108' id='Page_108'>108</a></span>
Animals which are found within Living Animals.”
This work, a veritable treatise of comparative
parasitology, published in 1684, caused the great
naturalist, physician, and poet to be regarded as the
father of that science. He tells us that in dissecting
a curious dicephalous <i>Vipera aspis</i>, caught at Pisa, he
found within the intestines a number of roundworms
(<i>Ascaris cephaloptera</i>), and on the surface of one of
the two lobes of the liver five cysts enclosing a small
worm, which he rightly ascribed to the same species.</p>

<p class='c032'>The parasites of snakes are here enumerated by
Dr. L. W. Sambon, in systematic order.</p>

<p class='c032'><span class='sc'>Arthropoda.</span>—Two families of the class Arachnida,
the Ixodidæ and the Linguatulidæ, furnish
numerous species parasitic on snakes.</p>

<p class='c032'>Of the Ticks (Ixodidæ) we find, as a rule, species
of the genera <i>Amblyomma</i> and <i>Aponomma</i>, the
latter genus being almost entirely confined to
Reptiles. A single species of the genus <i>Hæmaphysalis</i>
(<i>H. punctata</i>, Can. and Franz, 1877) has
been reported once from <i>Vipera aspis</i>. A few larval
forms found on various snakes have been reported
under the generic name <i>Ixodes</i>, but they probably
belong either to <i>Amblyomma</i> or <i>Aponomma</i>.</p>

<p class='c032'>The Ophidian Tick-parasites, like those of
mammals, birds, lizards, and tortoises, appear to
be in many cases the means of transmission of
protozoal infections from snake to snake.</p>

<p class='c032'>The Tongue-worms (Linguatulidæ) are, without
<span class='pagenum'><a name='Page_109' id='Page_109'>109</a></span>
doubt, of the greatest possible interest. Their
systematic position has ever been a puzzle to
zoologists, and even now is a matter of controversy.
They have been looked upon as Hirudinea
by Winsberg (1765), Cestoda by Chabert (1787),
Acanthocephala by Humboldt (1808), Trematoda by
Rudolphi (1809), and Nematoda by Nordmann (1832).
It was Van Beneden (1848) who first recognized
their Arthropod nature, but he placed them amongst
the Crustacea. Schubärt (1853) suggested that their
proper position is amongst the Mites (Acarina), and
Leuckart (1860) adduced important anatomical and
embryological evidence in support of this view,
which was confirmed by Railliet in 1883 and by
Sambon in 1910.</p>

<p class='c032'>No less than three out of the four genera of
Linguatulids so far established are represented by
species parasitic on snakes. They are the genera
<i>Porocephalus</i>, <i>Reighardia</i>, and <i>Raillietiella</i>.</p>

<p class='c032'>The genus <i>Porocephalus</i> is of special interest,
because some of its species, such as <i>Porocephalus
armillatus</i>, a parasite of African Pythons (<i>Python
regius</i>, <i>P. sebæ</i>) and Puff-adders (<i>Bitis arietans</i>,
<i>B. nasicornis</i>, <i>B. gabonica</i>), and <i>Porocephalus moniliformis</i>,
a parasite of Oriental Pythons (<i>Python
molurus</i>, <i>P. reticulatus</i>), are, in their nymphal stage,
deadly parasites of mammals, including man.</p>

<p class='c032'>The genus <i>Reighardia</i> was established by Professor
H. B. Ward, in 1899, for a Linguatulid of gulls and
<span class='pagenum'><a name='Page_110' id='Page_110'>110</a></span>
terns, first described, in 1861, by De Filippi. In
1910 Sambon included in this genus other similarly
structured Linguatulids from crocodiles, monitors,
and snakes.</p>

<p class='c032'>The genus <i>Raillietiella</i> was established by Sambon
in 1910 for a Linguatulid (<i>Raillietiella boulengeri</i>) of
the African Puff-adders (<i>Bitis arietans</i>, <i>B. gabonica</i>).
Amongst the characters of this genus is one of
great structural and phylogenetic importance—viz.,
the position of the female sexual orifice at the
anterior end of the abdomen, whilst in the other
known genera it is at the posterior extremity.</p>

<p class='c032'>According to Prowazek, Sambon, and Laveran, the
Ophidian Linguatulids, which live as blood-suckers
in the air-passages of their hosts, are able to
foster and transmit the hæmogregarines of these
hosts.</p>

<p class='c032'><span class='sc'>Acanthocephala.</span>—The early encysted stages of
several species of Thorn-headed worms (<i>Acanthocephala</i>),
belonging to the family <i>Echinorhynchidæ</i>,
have been reported from snakes belonging to very
different genera, such as <i>Boa</i>, <i>Tropidonotus</i>, <i>Zamenis</i>,
<i>Drymobius</i>, <i>Xenodon</i>, <i>Dipsadomorphus</i>, <i>Oxyrhopus</i>,
<i>Erythrolamprus</i>, <i>Diemenia</i>, <i>Naja</i>, <i>Elaps</i>, <i>Vipera</i>,
<i>Lachesis</i>. Their further development probably
occurs in ophiophagous birds. Thus, <i>Echinorhynchus
oligacanthoides</i>, Rud., the immature stages of which
occur encapsuled within the body cavity of <i>Lachesis
lanceolatus</i> and other neotropical snakes, when adult
<span class='pagenum'><a name='Page_111' id='Page_111'>111</a></span>
is found attached to the intestinal mucosa of <i>Milvus
bidentatus</i>.</p>

<p class='c032'><span class='sc'>Nematoda.</span>—The roundworms (<i>Nematoda</i>) so
far described from snakes belong to the families
Ascaridæ, Strongylidæ, Trichotrachelidæ, and
Filariidæ. Some of the genera belonging to these
families, such as <i>Cucullanus</i>, <i>Nematoxys</i>, <i>Oxysoma,</i>
are as yet represented by a single species in a single
host; others, such as <i>Ascaris</i>, <i>Polydelphis</i>, <i>Heterakis</i>,
<i>Strongylus</i>, <i>Diaphanocephalus</i>, <i>Physaloptera</i>, <i>Trichosoma</i>,
number already several species more or less
widely distributed.</p>

<p class='c032'>Eelworm infection (ascariasis) is very common in
snakes, and not infrequently the infection is a heavy
one; Sambon twice found over fifty specimens
of <i>Polydelphis</i> in Puff-adders (<i>Bitis arietans</i>). This
investigator has shown that the snake eelworms
undergo an encysted stage of development within
the body cavity of their hosts before migrating into
the intestinal lumen for the purpose of fertilization
and oviposition. Thus, Redi was quite right in
considering the immature, encysted forms found in
one of the livers of his double-headed Asp as
belonging to the same species of eelworm (<i>Ascaris
cephaloptera</i>) as that which the snake harboured in
its intestine.</p>

<p class='c032'>Professor A. Railliet, whilst examining specimens
of <i>Polydelphis</i> which had been preserved for nearly
two months in a 3 per cent. solution of formalin,
<span class='pagenum'><a name='Page_112' id='Page_112'>112</a></span>
found that the ova within their uterine tubes had
undergone development, and still contained living
embryos; indeed, some of these hatched under the
microscope, and moved very actively in the preserving
fluid. This is in no way surprising, because
even after several years of preservation in formalin
solution the embryos of other species of eelworms
(<i>Ascaris equorum</i>, <i>A. marginata</i>) have been found in
a living condition.</p>

<p class='c032'><span class='sc'>Trematoda.</span>—The Flukes (<i>Trematoda</i>) of snakes,
so far described, belong to the following genera:
<i>Agamodistomum</i>, <i>Astiotrema</i>, <i>Brachylaimus</i>, <i>Cotylotretus</i>,
<i>Dicrocœlium</i>, <i>Diplodiscus</i>, <i>Distoma</i>, <i>Halipegus</i>,
<i>Lecithodendrium</i>, <i>Metorchis</i>, <i>Opisthogonimus</i>, <i>Opisthorchis</i>,
<i>Plagiorchis</i>, <i>Saphedera</i>, <i>Telorchis</i>, <i>Tetracotyle</i>,
<i>Zeugorchis</i>.</p>

<p class='c032'><span class='sc'>Cestoda.</span>—Save a few larval forms (<i>Cysticercoides</i>,
<i>Piestocystis</i>, <i>Sparganum</i>), the known tapeworms
(<i>Cestoda</i>) of the Ophidia belong to the genera
<i>Bothridium</i> and <i>Proteocephalus</i>.</p>

<p class='c032'><span class='sc'>Protozoa.</span>—Numerous species of Hæmogregarines
have been described from snakes. As a rule the
forms seen in the peripheral blood are sporonts, the
schizogonic cycle occurring in the lungs. The
sporonts do not greatly alter their host cells; they
are invariably doubled up within a more or less
thick capsule. Some species show a marked sexual
differentiation, others not. <i>Trypanosomes</i>, <i>Spiroechaudinniæ</i>,
and <i>Plasmodidæ</i> have also been described
from the blood of various snakes.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_113' id='Page_113'>113</a></span>
Within the alimentary tube have been found
species of <i>Trichomonas</i> and <i>Caryospora</i>.</p>

<p class='c032'><span class='sc'>Bacteria.</span>—Acid-fast bacilli have been described
in tubercular lesions found in snakes by Sibley,
Gibbs and Shurley, Shattock, Hausemann, and
Sambon.</p>

<p class='c032'>The so-called “canker,” which so frequently
develops in the oral cavity of captive snakes, is also
a bacterial disease, due to a specific bacterium of
thick, rod-shaped form.</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    LIST OF PARASITES HITHERTO<br />
    RECORDED FROM EUROPEAN SNAKES
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    TROPIDONOTUS NATRIX, L.
  </div>
</div>

<p class='c035'><span class='sc'>Acanthocephala.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Echinorhynchus inæqualis</i>, Rudolphi.<br />
    <i>Echinorhynchus polyacanthus</i>, Creplin.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Nematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Strongylus auricularis</i>, Zeder.<br />
    <i>Strongylus catanensis</i>, Rizzo.<br />
    <i>Trichosoma mingazzini</i>, Rizzo.<br />
    <i>Oxysoma brevicaudatum</i>, Zeder.<br />
    <i>Nematoxys commutatus</i>, Rudolphi.<br />
    <i>Ascaris cephaloptera</i>, Rudolphi.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Trematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Opisthorchis caudatum</i>, Polonio.<br />
    <i>Dicrocœlium assula</i>, Dujardin.<br />
    <i>Diplodiscus conicum</i>, Polonio.<br />
    <i>Tetracotyle colubri</i>, v. Linstow.<br />

<span class='pagenum'><a name='Page_114' id='Page_114'>114</a></span>
<i>Distoma acervocalciferum</i>, Gastaldi.<br />
    <i>Distoma allostomum</i>, Diesing.<br />
    <i>Distoma nematoides</i>, Mühling.<br />
    <i>Saphedera naja</i>, Rudolphi.<br />
    <i>Brachylaimus signatum</i>, Dujardin.<br />
    <i>Telorchis ercolanii</i>, Monticelli.<br />
    <i>Lecithodendrium nigrovenosum</i>, Bellingham.<br />
    <i>Plagiorchis mentulatus</i>, Rudolphi.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Cestoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Ligula panceri</i>, Polonio.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    TROPIDONOTUS TESSELLATUS, <span class='sc'>Laur.</span>
  </div>
</div>

<p class='c035'><span class='sc'>Nematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Strongylus denudatus</i>, Rudolphi.<br />
    <i>Physaloptera abbreviata</i>, Rudolphi.<br />
    <i>Physaloptera striata</i>, v. Linstow.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Trematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Plagiorchis mentulatus</i>, Rudolphi.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    TROPIDONOTUS VIPERINUS, <span class='sc'>Latr.</span>
  </div>
</div>

<p class='c035'><span class='sc'>Acanthocephala.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Echinorhynchus lobianchii</i>, Monticelli.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Trematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Distoma allostomum</i>, Diesing.<br />
    <i>Opisthorchis caudatum</i>, Polonio.<br />
    <i>Telorchis ercolanii</i>, Monticelli.<br />
    <i>Astiotrema monticellii</i>, Stossich.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Cestoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Ligula pancerii</i>, Polonio.
    </p>
  </div>
</div>

<p class='c035'>
<span class='pagenum'><a name='Page_115' id='Page_115'>115</a></span>
<span class='sc'>Protozoa.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Hæmogregarina viperina</i>, Billet.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    ZAMENIS GEMONENSIS, <span class='sc'>Laur.</span>
  </div>
</div>

<p class='c035'><span class='sc'>Acanthocephala.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Echinorhynchus cinctus</i>, Rudolphi.<br />
    <i>Echinorhynchus polyacanthus</i>, Creplin.<br />
    <i>Echinorhynchus heterorhynchus</i>, Parona.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Nematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Strongylus catanensis</i>, Rizzo.<br />
    <i>Filaria parvomucronata</i>, Rizzo.<br />
    <i>Trichosoma sonsinoi</i>, Parona.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Trematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Distoma subflavum</i>, Sonsino.<br />
    <i>Brachylaimus baraldii</i>, Sonsino.<br />
    <i>Saphedera naja</i>, Rudolphi.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Cestoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Cysticercus acanthotetra</i>, Parona.<br />
    <i>Cysticercoides rostratus</i>, Mingazzini.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    COLUBER QUATUORLINEATUS, <span class='sc'>Lacep.</span>
  </div>
</div>

<p class='c035'><span class='sc'>Acanthocephala.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Echinorhynchus oligacanthus</i>, Rudolphi.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Nematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Ascaris cephaloptera</i>, Rudolphi.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Trematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Plagiorchis sauromates</i>, Poirier.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Protozoa.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Hæmogregarina</i>, sp.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >

<span class='pagenum'><a name='Page_116' id='Page_116'>116</a></span>
COLUBER LONGISSIMUS, <span class='sc'>Laur.</span>
  </div>
</div>

<p class='c035'><span class='sc'>Protozoa.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Hæmogregarina colubri</i>, Börner.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    CORONELLA AUSTRIACA, <span class='sc'>Laur.</span>
  </div>
</div>

<p class='c035'><span class='sc'>Nematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Tricheilonema megalochilum</i>, Diesing.<br />
    <i>Physaloptera colubri</i>, Rudolphi.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Cestoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Piestocystis dithyridium</i>, Diesing.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Protozoa.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Monocercomonas colubrorum</i>, Hammersch.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    CORONELLA GIRONDICA, <span class='sc'>Daud.</span>
  </div>
</div>

<p class='c035'><span class='sc'>Protozoa.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Hæmogregarina coronellæ</i>, França.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    VIPERA BERUS, L.
  </div>
</div>

<p class='c035'><span class='sc'>Nematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Physaloptera dentata</i>, v. Linstow.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Trematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Agamodistomum viperæ</i>, v. Linstow.<br />
    <i>Tetracotyle colubri</i>, v. Linstow.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    VIPERA ASPIS, L.
  </div>
</div>

<p class='c035'><span class='sc'>Arthropoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Hæmaphysalis punctata</i>, Can. &amp; Franz.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Acanthocephala.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Echinorhynchus cinctus</i>, Rudolphi.
    </p>
  </div>
</div>

<p class='c035'>
<span class='pagenum'><a name='Page_117' id='Page_117'>117</a></span>
<span class='sc'>Nematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Ascaris cephaloptera</i>, Rudolphi.<br />
    <i>Diaphanocephalus viperæ</i>, Rudolphi.
    </p>
  </div>
</div>

<p class='c035'><span class='sc'>Protozoa.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Caryospora simplex</i>, Léger.<br />
    <i>Hæmogregarina samboni</i>, Giordano.
    </p>
  </div>
</div>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    VIPERA AMMODYTES, L.
  </div>
</div>

<p class='c035'><span class='sc'>Nematoda.</span></p>

<div class='nf-left-c0'>
<div class='nf-left c030'  >
    <p>
    <i>Ascaris ammodytis</i>, Rudolphi.<br />
    <i>Ascaris cephaloptera</i>, Rudolphi.
    </p>
  </div>
</div>

<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_118' id='Page_118'>118</a></span>
  <h2 id='ch12' class='c003'>CHAPTER XII<br /> <br />DISTRIBUTION</h2>
</div>
<p class='drop-capa c033'    >Representatives of the order Ophidia are
found over the whole world, with the exception
of Iceland, Ireland, and New Zealand, between the
Northern limit of 67° in Europe (<i>Vipera berus</i>), 60° in
Asia (<i>Vipera berus</i>), and 52° in America (<i>Tropidonotus
ordinatus</i>), and the Southern limit of 44° (<i>Philodryas
schotti</i>). The highest altitudes reached by them are
14,000 feet in the Himalayas (<i>Tropidonotus baileyi</i>),
9,700 feet in the Alps (<i>Vipera aspis</i>), and 9,000 feet
in the Andes (<i>Liophis albiventris</i>). They are most
numerous between the tropics, and the number of
species gradually diminishes to the North and South.</p>

<p class='c032'>For the purpose of showing the distribution of the
principal groups, we will follow the divisions into
families and subfamilies enumerated above (p. <a href='#Page_4'>4</a>).</p>

<p class='c032'><i>Typhlopidæ.</i>—S.E. Europe, S. Asia, Africa, Australia
(exclusive of Tasmania), C. and S. America,
and W. Indies.</p>

<p class='c032'><i>Glauconiidæ.</i>—S. Asia (as far E. as Sind), Africa
(exclusive of Madagascar), C. America (extending into
the S. parts of N. America), S. America.</p>

<p class='c032'><i>Pythoninæ.</i>—S. Asia, Africa (exclusive of Madagascar),
Australia (exclusive of Tasmania), C. America.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_119' id='Page_119'>119</a></span>
<i>Boinæ.</i>—S.E. Europe, C. and S. Asia, N. Africa,
Madagascar, Mauritius, W. Polynesia, S.W. of
N. America, C. and S. America, and W. Indies.</p>

<p class='c032'><i>Ilysiidæ.</i>—S.E. Asia, S. America.</p>

<p class='c032'><i>Uropeltidæ.</i>—India and Ceylon.</p>

<p class='c032'><i>Xenopeltidæ.</i>—S.E. Asia.</p>

<p class='c032'><i>Acrochordinæ.</i>—S.E. Asia, C. America.</p>

<p class='c032'><i>Colubrinæ.</i>—The whole range of Ophidia, except
Tasmania.</p>

<p class='c032'><i>Dasypeltinæ.</i>—Africa (exclusive of Madagascar).</p>

<p class='c032'><i>Homalopsinæ.</i>—S.E. Asia, N. Australia.</p>

<p class='c032'><i>Dipsadomorphinæ.</i>—S. Europe, C. and S. Asia,
Africa, Australia (exclusive of Tasmania), C. America
(extending into the S. parts of N. America),
S. America.</p>

<p class='c032'><i>Elachistodontinæ.</i>—India.</p>

<p class='c032'><i>Hydrophiinæ.</i>—Indian and Pacific Oceans.</p>

<p class='c032'><i>Elapinæ.</i>—S. Asia, Africa (exclusive of Madagascar),
Australia and Tasmania, Fiji Islands, C. America
(extending into the S. parts of N. America),
S. America.</p>

<p class='c032'><i>Amblycephalidæ.</i>—S.E. Asia, C. and S. America.</p>

<p class='c032'><i>Viperinæ.</i>—Europe, Asia, Africa (exclusive of
Madagascar).</p>

<p class='c032'><i>Crotalinæ.</i>—S.E. Europe, Asia, America.</p>

<p class='c032'>The Zoogeographical Regions into which the world
is usually divided (Palæarctic or Europo-Asiatic,
Oriental or Indian, Ethiopian or African, Australian,
Nearctic or North American, Neotropical or South
<span class='pagenum'><a name='Page_120' id='Page_120'>120</a></span>
American) do not lend themselves any better than
the ordinary divisions of physical geography to the
study of the distribution of Snakes. Contrary to
what we find in dealing with the Tortoises, Australia
does not show any special affinity to South America,
and, as in the case of the Lizards, it must be
regarded as an impoverished extension of the Indo-Malay
fauna; as with the Lizards, also, Europe and
Africa hang together, whilst Madagascar stands apart,
distinguished by many negative features and some
points of agreement with South America (Boidæ).
There is a greater difference between the Snakes of
Europe and those of Eastern Asia than there is
between the latter and those of North America,
whilst in Lizards a primary distinction must be made
between the Old World and the New. Southern
Asia east of Persia (the Oriental Region) is the great
Ophidian centre, all the groups mentioned above, with
the exception of the Dasypeltinæ, having representatives
within its limits, and a large and very distinct
family, the Uropeltidæ, being confined to it. The
Pythoninæ occur along with the Boinæ, the Viperinæ
with the Crotalinæ, and the Elapinæ are represented
by varied forms, as they are also in Africa and still
more in Australia, where they form the overwhelming
majority, and in some parts, as well as in
Tasmania, the exclusive Ophidian population. The
coasts of India and Malaya are also the home of the
great majority of the Hydrophiinæ. Large genera
<span class='pagenum'><a name='Page_121' id='Page_121'>121</a></span>
like <i>Tropidonotus</i>, <i>Zamenis</i>, and <i>Coluber</i>, extend over
the Europo-Asiatic and North American regions, but
they are equally well represented in the Oriental.
The great difference between Madagascar and Africa
is, as we have said, very striking. Madagascar possesses
Boidæ generically identical with those of South
America, but otherwise only Typhlopidæ, Colubrinæ,
and Dipsadomorphinæ; whilst in the greater part of
Africa the Boinæ are replaced by the Pythoninæ, and
the Glauconiidæ, Elapinæ, and Viperinæ are generally
distributed. North America agrees with Asia
and South America in its Crotalinæ, otherwise its
Ophidian fauna is not very different from that of
Europe, although much richer, and South America
shares the Glauconiidæ with Africa and the Ilysiidæ
with Southern Asia. South America is rich in
Colubrinæ and Dipsadomorphinæ, nearly all generically
different from those of other parts of the world,
and the Elapinæ are represented by the single genus
<i>Elaps</i>, with many species, two of which extend to
the southern parts of North America.</p>

<p class='c032'>This rapid sketch of the principal facts of Ophidian
distribution suffices to show how difficult it would be
to frame geographical regions that would give expression
to these facts. Such regions would necessarily
be very different from those adopted in dealing with
the distribution of the other divisions of the class
Reptilia. This is a task which need not be attempted
on the present occasion.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_122' id='Page_122'>122</a></span>
A few words as to the salient characters of
the European fauna, which is a poor one as compared
with other parts of the world. The single
species of the genera <i>Typhlops</i> and <i>Eryx</i> must be
regarded as outposts from South-Western Asia; the
single species of <i>Ancistrodon</i>, which extends from
Central Asia into a very small territory to the south-east,
is also an Asiatic type. The genera <i>Tropidonotus</i>,
<i>Zamenis</i>, <i>Coluber</i>, <i>Coronella</i>, and <i>Contia</i>, are
characteristic of the Northern Hemisphere, and the
first three are, besides, equally well represented in
the Oriental region; a few species of <i>Tropidonotus</i> are
also found in Africa and Madagascar. <i>Cœlopeltis</i>,
<i>Macroprotodon</i>, and <i>Tarbophis</i> are the northern outposts
of an Afro-Indian group, although, with
the exception of the third, exclusively confined to
the circum-Mediterranean district. The genus <i>Vipera</i>
is also represented in East Africa and in Southern
Asia, but the species <i>V. berus</i> is essentially a northern
type, extending to the highest latitude reached by
any snake, and ranging all over Northern Asia to the
Amur and Sachalien. The same species reaches the
greatest altitude at which any snake has been observed
on the northern side of the Alps—viz., 9,000 feet.</p>

<p class='c032'>Of the twenty-eight species inhabiting Europe,
only two are generally distributed: <i>Tropidonotus
natrix</i> and <i>Coronella austriaca</i>. One is to be regarded
as a northern form, although occurring locally in the
south: <i>Vipera berus</i>. It is the reverse with <i>Coluber longissimus</i>.
<span class='pagenum'><a name='Page_123' id='Page_123'>123</a></span>
The others may be described as southern
forms, two only as ranging from west to east:
<i>Zamenis gemonensis</i> and <i>Cœlopeltis monspessulana</i>;
one of more central habitat: <i>Vipera ursinii</i>. The
remainder may be divided into two groups—those of
more western, and those of more eastern distribution.
To the first group belong <i>Tropidonotus viperinus</i>,
<i>Zamenis hippocrepis</i>, <i>Coluber scalaris</i>, <i>Coronella girondica</i>,
<i>Macroprotodon cucullatus</i>, <i>Vipera aspis</i> and <i>Vipera
latastii</i>; to the second, <i>Typhlops vermicularis</i>, <i>Eryx
jaculus</i>, <i>Tropidonotus tessellatus</i>, <i>Zamenis dahlii</i>, <i>Coluber
quatuorlineatus</i>, <i>dione</i>, <i>leopardinus</i>, <i>Contia modesta</i>,
<i>Tarbophis fallax</i> and <i>iberus</i>, <i>Vipera renardi</i>, <i>ammodytes</i>,
<i>lebetina</i>, and <i>Ancistrodon halys</i>.</p>

<p class='c032'>A remarkable fact in the distribution of European
Snakes is the altitudinal range of <i>Vipera berus</i>,
<i>V. aspis</i>, and <i>V. ursinii</i>. The first being the northernmost
snake, generally distributed in Northern
Europe and more locally in the south, should, one
would expect, be a mountain form in the south.
This is so in Switzerland, where it occurs chiefly
between 2,500 and 9,000 feet, on the northern aspect
of the Alps, whilst <i>V. aspis</i> lives at altitudes below
5,000 feet; but on the southern aspect of the same
chain things are reversed, and <i>V. berus</i> is replaced
by <i>V. aspis</i>, which reaches an altitude of 9,700 feet,
whilst the former shows a tendency to abandon the
mountains, and has established itself in a few localities
in the plain of North Italy. Again, in France
<span class='pagenum'><a name='Page_124' id='Page_124'>124</a></span>
<i>V. berus</i> is the northern and <i>V. aspis</i> the southern
species, yet the latter is the only one found on the
French side of the Pyrenees (up to 7,250 feet), whilst
the former reappears in North-Western Spain and
Portugal at very low altitudes, even at sea-level.
<i>V. ursinii</i> is a mountain form in Italy (Abruzzi), in
France (Basses-Alpes), and in the Balkan Peninsula
(up to 6,800 feet); but it is restricted to the plain in
Lower Austria and Hungary, where <i>V. berus</i> occurs
only in the mountains.</p>

<p class='c032'>Only three species are entirely confined to Europe:</p>

<p class='c032'><i>Coluber scalaris</i>, <i>Vipera ursinii</i>, and <i>V. aspis</i>.</p>

<p class='c032'>Of the species which range outside Europe, the
following occur both in Western Asia and in North
Africa:</p>

<p class='c032'><i>Eryx jaculus</i>, <i>Tropidonotus natrix</i>, <i>Cœlopeltis monspessulana</i>,
<i>Vipera lebetina</i>.</p>

<p class='c032'>In Western Asia and the North-East of Egypt:</p>

<p class='c032'><i>Tropidonotus tessellatus</i>, <i>Zamenis dahlii</i>.</p>

<p class='c032'>In Western Asia:</p>

<p class='c032'><i>Typhlops vermicularis</i>, <i>Zamenis gemonensis</i>, <i>Coluber
quatuorlineatus</i>, <i>C. dione</i>, <i>C. longissimus</i>, <i>C. leopardinus</i>,
<i>Coronella austriaca</i>, <i>Contia modesta</i>, <i>Tarbophis fallax</i>,
<i>T. iberus</i>, <i>Vipera renardi</i>, <i>V. berus</i>, <i>V. ammodytes</i>,
<i>Ancistrodon halys</i>.</p>

<p class='c032'>In North Africa:</p>

<p class='c032'><i>Macroprotodon cucullatus.</i></p>

<p class='c032'>
<span class='pagenum'><a name='Page_125' id='Page_125'>125</a></span>
In North-West Africa:</p>

<p class='c032'><i>Tropidonotus viperinus</i>, <i>Zamenis hippocrepis</i>, <i>Coronella
girondica</i>, <i>Vipera latastii</i>.</p>

<p class='c032'>The following lists will help to elucidate the
distribution of the snakes in the different parts of
Europe:</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    I. <span class='sc'>Scandinavia</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix</i> (as far north as 65°).</p>

<p class='c032'>2. <i>Coronella austriaca</i> (as far north as 63°).</p>

<p class='c032'>3. <i>Vipera berus</i> (as far north as 67°).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    II. <span class='sc'>Great Britain</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix</i> (England and Wales, extreme
south-east of Scotland).</p>

<p class='c032'>2. <i>Coronella austriaca</i> (Surrey, Berkshire, Hampshire,
and Dorsetshire).</p>

<p class='c032'>3. <i>Vipera berus.</i></p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    III. <span class='sc'>Belgium and Holland</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix.</i></p>

<p class='c032'>2. <i>Coronella austriaca.</i></p>

<p class='c032'>3. <i>Vipera berus.</i></p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    IV. <span class='sc'>Germany and Denmark</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix.</i></p>

<p class='c032'>2. <i>Tropidonotus tessellatus</i> (Middle Rhine and
Moselle, Saxony).</p>

<p class='c032'>3. <i>Coluber longissimus</i> (Denmark, Schlangenbad,
Treves).</p>

<p class='c032'>
<span class='pagenum'><a name='Page_126' id='Page_126'>126</a></span>
4. <i>Coronella austriaca.</i></p>

<p class='c032'>5. <i>Vipera berus.</i></p>

<p class='c032'>6. <i>Vipera aspis</i> (Black Forest, Lorraine).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    V. <span class='sc'>France and Switzerland, exclusive of Ticino</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix.</i></p>

<p class='c032'>2. <i>Tropidonotus viperinus</i> (as far north as South
Brittany and Fontainebleau).</p>

<p class='c032'>3. <i>Zamenis gemonensis</i> (south, locally as far north
as the Sarthe and Aube).</p>

<p class='c032'>4. <i>Coluber longissimus</i> (locally as far north as
South Brittany, South Normandy, and Fontainebleau).</p>

<p class='c032'>5. <i>Coluber scalaris</i> (Mediterranean Littoral).</p>

<p class='c032'>6. <i>Coronella austriaca.</i></p>

<p class='c032'>7. <i>Coronella girondica</i> (south and west as far
north as the Charente-Inférieure).</p>

<p class='c032'>8. <i>Cœlopeltis monspessulana</i> (Mediterranean Littoral).</p>

<p class='c032'>9. <i>Vipera ursinii</i> (Basses-Alpes).</p>

<p class='c032'>10. <i>Vipera berus</i> (as far south as the Loire basin,
the Central Plateau, and the Alps).</p>

<p class='c032'>11. <i>Vipera aspis</i> (as far north as the Loire basin,
Fontainebleau, and Lorraine).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    VI. <span class='sc'>Spain and Portugal</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix.</i></p>

<p class='c032'>2. <i>Tropidonotus viperinus.</i></p>

<p class='c032'>
<span class='pagenum'><a name='Page_127' id='Page_127'>127</a></span>
3. <i>Zamenis gemonensis</i> (Catalonia).</p>

<p class='c032'>4. <i>Zamenis hippocrepis</i> (absent from the north).</p>

<p class='c032'>5. <i>Coluber longissimus</i> (Andalucia).</p>

<p class='c032'>6. <i>Coluber scalaris.</i></p>

<p class='c032'>7. <i>Coronella austriaca</i> (north and north-west).</p>

<p class='c032'>8. <i>Coronella girondica.</i></p>

<p class='c032'>9. <i>Cœlopeltis monspessulana.</i></p>

<p class='c032'>10. <i>Macroprotodon cucullatus</i> (centre and south,
Baleares).</p>

<p class='c032'>11. <i>Vipera berus</i> (north-west).</p>

<p class='c032'>12. <i>Vipera aspis</i> (Pyrenees).</p>

<p class='c032'>13. <i>Vipera latastii</i> (absent from the north).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    VII. <span class='sc'>Italy, with Ticino and Corsica</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix.</i></p>

<p class='c032'>2. <i>Tropidonotus tessellatus</i> (as far south as Naples;
absent from the islands).</p>

<p class='c032'>3. <i>Tropidonotus viperinus</i> (Liguria, Piedmont,
Ticino, Corsica, Sardinia, Sicily).</p>

<p class='c032'>4. <i>Zamenis gemonensis.</i></p>

<p class='c032'>5. <i>Zamenis hippocrepis</i> (Sardinia).</p>

<p class='c032'>6. <i>Coluber quatuorlineatus</i> (south and Sicily).</p>

<p class='c032'>7. <i>Coluber longissimus</i> (absent from Corsica).</p>

<p class='c032'>8. <i>Coluber leopardinus</i> (south and Sicily).</p>

<p class='c032'>9. <i>Coronella austriaca</i> (absent from Corsica and
Sardinia).</p>

<p class='c032'>10. <i>Coronella girondica</i> (absent from Corsica and
Sardinia).</p>

<p class='c032'>11. <i>Cœlopeltis monspessulana</i> (Western Liguria,
Sicily).</p>

<p class='c032'>
<span class='pagenum'><a name='Page_128' id='Page_128'>128</a></span>
12. <i>Vipera ursinii</i> (Abruzzi).</p>

<p class='c032'>13. <i>Vipera berus</i> (the Continental part only).</p>

<p class='c032'>14. <i>Vipera aspis</i> (absent from Corsica and
Sardinia).</p>

<p class='c032'>15. <i>Vipera ammodytes</i> (Northern Venetia).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    VIII. <span class='sc'>Austria-Hungary, without Balkan States</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix.</i></p>

<p class='c032'>2. <i>Tropidonotus tessellatus.</i></p>

<p class='c032'>3. <i>Zamenis gemonensis</i> (South Tyrol, Littoral,
South Hungary).</p>

<p class='c032'>4. <i>Coluber quatuorlineatus</i> (Istria).</p>

<p class='c032'>5. <i>Coluber longissimus.</i></p>

<p class='c032'>6. <i>Coluber leopardinus</i> (Istria).</p>

<p class='c032'>7. <i>Coronella austriaca.</i></p>

<p class='c032'>8. <i>Coronella girondica</i> (South Tyrol).</p>

<p class='c032'>9. <i>Cœlopeltis monspessulana</i> (Istria).</p>

<p class='c032'>10. <i>Tarbophis fallax</i> (Istria).</p>

<p class='c032'>11. <i>Vipera ursinii</i> (Lower Austria, Littoral, Hungary).</p>

<p class='c032'>12. <i>Vipera berus.</i></p>

<p class='c032'>13. <i>Vipera aspis</i> (South Tyrol, Littoral).</p>

<p class='c032'>14. <i>Vipera ammodytes</i> (South Tyrol, Styria,
Carinthia, Carniola, Littoral, South Hungary).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    IX. <span class='sc'>Balkan Peninsula and Archipelago</span>
  </div>
</div>

<p class='c032'>1. <i>Typhlops vermicularis</i> (Greece, Turkey, Bulgaria).</p>

<p class='c032'>
<span class='pagenum'><a name='Page_129' id='Page_129'>129</a></span>
2. <i>Eryx jaculus</i> (Greece, Turkey, Roumania).</p>

<p class='c032'>3. <i>Tropidonotus natrix.</i></p>

<p class='c032'>4. <i>Tropidonotus tessellatus.</i></p>

<p class='c032'>5. <i>Zamenis gemonensis.</i></p>

<p class='c032'>6. <i>Zamenis dahlii</i> (coast of the Adriatic, Greece).</p>

<p class='c032'>7. <i>Coluber quatuorlineatus.</i></p>

<p class='c032'>8. <i>Coluber longissimus.</i></p>

<p class='c032'>9. <i>Coluber leopardinus.</i></p>

<p class='c032'>10. <i>Coronella austriaca.</i></p>

<p class='c032'>11. <i>Cœlopeltis monspessulana</i> (West Coast, Greece,
and islands).</p>

<p class='c032'>12. <i>Tarbophis fallax</i> (West Coast, Greece and
islands, Constantinople).</p>

<p class='c032'>13. <i>Vipera ursinii</i> (Bulgaria, Bosnia, Herzegovina,
Montenegro).</p>

<p class='c032'>14. <i>Vipera berus</i> (Bosnia, Herzegovina, Roumania).</p>

<p class='c032'>15. <i>Vipera aspis</i> (Bosnia).</p>

<p class='c032'>16. <i>Vipera ammodytes.</i></p>

<p class='c032'>17. <i>Vipera lebetina</i> (Cyclades).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    X. <span class='sc'>Russia</span>
  </div>
</div>

<p class='c032'>1. <i>Tropidonotus natrix</i> (as far north as 60°).</p>

<p class='c032'>2. <i>Tropidonotus tessellatus</i> (south).</p>

<p class='c032'>3. <i>Zamenis gemonensis</i> (south).</p>

<p class='c032'>4. <i>Zamenis dahlii</i> (Caucasus).</p>

<p class='c032'>5. <i>Coluber quatuorlineatus</i> (south).</p>

<p class='c032'>6. <i>Coluber dione</i> (south, between Volga and Ural).</p>

<p class='c032'>7. <i>Coluber longissimus</i> (south, Poland).</p>

<p class='c032'>
<span class='pagenum'><a name='Page_130' id='Page_130'>130</a></span>
8. <i>Coluber leopardinus</i> (Crimea).</p>

<p class='c032'>9. <i>Coronella austriaca</i> (as far north as 57°).</p>

<p class='c032'>10. <i>Contia modesta</i> (Caucasus).</p>

<p class='c032'>11. <i>Tarbophis iberus</i> (Caucasus).</p>

<p class='c032'>12. <i>Vipera renardi</i> (south).</p>

<p class='c032'>13. <i>Vipera berus</i> (as far north as 64°).</p>

<p class='c032'>14. <i>Ancistrodon halys</i> (south, between Volga and
Ural).</p>

<p class='c036'>Without attempting anything like a complete
bibliography, we have compiled a list of faunistic
works and papers dealing with the snakes of Europe:</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Europe in General</span>
  </div>
</div>

<p class='c032'><span class='sc'>Schreiber, E.</span>: Herpetologia Europæa. Zweite
Auflage, Jena, 1912, 8vo.</p>

<p class='c032'><span class='sc'>Steinheil, F.</span>: Die Europaeischen Schlangen.
Kupferdrucktafeln nach Photographien der lebenden
Tiere. Jena, 1913, 4to. (in progress).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Great Britain</span>
  </div>
</div>

<p class='c032'><span class='sc'>Bell, T.</span>: A History of British Reptiles. 2nd
edit., London, 1849, 8vo.</p>

<p class='c032'><span class='sc'>Cook, M. C.</span>: Our Reptiles. London, 1865, 8vo.</p>

<p class='c032'><span class='sc'>Leighton, G.</span>: The Life-History of British
Serpents. Edinburgh and London, 1901, 8vo.</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>France</span>
  </div>
</div>

<p class='c032'><span class='sc'>Gadeau de Kerville, H.</span>: Faune de la Normandie.
IV. Reptiles. Paris, 1897, 8vo.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_131' id='Page_131'>131</a></span>
<span class='sc'>Lataste, F.</span>: Essai d’une Faune Herpétologique
de la Gironde. Bordeaux, 1876, 8vo.</p>

<p class='c032'><span class='sc'>Martin, R., et Rollinat, R.</span>: Vertébrés sauvages
du Département de l’Indre. Paris, 1894, 8vo.</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Switzerland</span>
  </div>
</div>

<p class='c032'><span class='sc'>Fatio, V.</span>: Faune des Vertébrés de la Suisse.
III. Reptiles et Batraciens. Geneva and Basle,
1872, 8vo.</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Spanish Peninsula</span>
  </div>
</div>

<p class='c032'><span class='sc'>Boscá, E.</span>: Catalogue des Reptiles et Amphibies
de la Péninsule Ibérique et des Îles Baléares (Bull.
Soc. Zool. France, 1880).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Italy</span>
  </div>
</div>

<p class='c032'><span class='sc'>Bonaparte, C. L.</span>: Iconografia della Fauna
Italica. II. Anfibi. Rome, 1832-1841, fol.</p>

<p class='c032'><span class='sc'>Camerano, L.</span>: Monografia degli Ofidi Italiani
(Mem. Acc. Torin., [2] xxxix., 1888, and xli., 1891).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Germany</span>
  </div>
</div>

<p class='c032'><span class='sc'>Dürigen, B.</span>: Deutschlands Amphibien und
Reptilien. Magdeburg, 1890-1897, 8vo.</p>

<p class='c032'><span class='sc'>Leydig, F.</span>: Ueber die Einheimischen Schlangen
(Abh. Senck. Ges., xiii., 1883).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Austrian Empire</span>
  </div>
</div>

<p class='c032'><span class='sc'>Werner, F.</span>: Die Reptilien und Amphibien
Oesterreich-Ungarns und der Occupationsländer.
Vienna, 1897, 8vo.</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >

<span class='pagenum'><a name='Page_132' id='Page_132'>132</a></span>
<span class='sc'>Greece</span>
  </div>
</div>

<p class='c032'><span class='sc'>Bedriaga, J. de</span>: Die Amphibien und Reptilien
Griechenlands (Bull. Soc. Nat. Mosc., 1881).</p>

<p class='c032'><span class='sc'>Bory de St. Vincent, J. B.</span>: Expédition Scientifique
de Morée. Reptiles. Paris, 1832-1835, 4to.,
fol. atlas.</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Bulgaria</span>
  </div>
</div>

<p class='c032'><span class='sc'>Kowatcheff, W. T.</span>: Herpetological Fauna of
Bulgaria. Philippopolis, 1912, 8vo. [Bulgarian
text.]</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Roumania</span>
  </div>
</div>

<p class='c032'><span class='sc'>Kiritzescu, C.</span>: Contribution à la Faune Herpétologique
de Roumanie. Sauriens et Ophidiens
(Bull. Soc. Rom. Bucarest, x., 1901).</p>

<div class='nf-center-c0'>
<div class='nf-center c034'  >
    <span class='sc'>Russia</span>
  </div>
</div>

<p class='c032'><span class='sc'>Nikolsky, A.</span>: Herpetologia Rossica. St. Petersburg,
1905, 4to. [Russian text.]</p>

<p class='c032'><span class='sc'>Strauch, A.</span>: Die Schlangen des Russischen
Reichs. St. Petersburg, 1873, 4to.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='chapter'>

<span class='pagenum'><a name='Page_133' id='Page_133'>133</a></span>
  <h2 id='ch13' class='c003'>CHAPTER XIII<br /> <br />SNAKES IN RELATION TO MAN</h2>
</div>
<p class='drop-capa c033'    >Under this head, the question of poisonous
snakes naturally occupies the first place. In
addition to what has been said above in Chapter VI.,
dealing with the anatomical and physiological aspects
of the subject, we have to allude to the accidents
caused by these dangerous reptiles, and the measures
taken to combat them.</p>

<p class='c032'>The enormous mortality for which snake-bite is
responsible in India is well known. Statistics establish
the fact that an average of 20,000 human lives
are thus lost annually: 24,264 is the official return
for 1911. In Australia, where highly poisonous snakes
of various genera and species abound, the fatal cases
are likewise very numerous, though less in proportion
than in South America, and no doubt also in
Africa. In the small island of Martinique, the Fer-de-Lance,
<i>Lachesis lanceolatus</i>, causes every year
the death of about 100 human creatures. Though
numerous in species, the poisonous snakes of Ceylon
cause a comparatively small mortality—200 per
annum.</p>

<p class='c032'>Modern research has resulted in the discovery of
<span class='pagenum'><a name='Page_134' id='Page_134'>134</a></span>
the only effective antidote for snake-venom intoxication:
the serotherapic treatment. An animal that
has been treated over a length of time with the
venom of a poisonous snake, such as a Cobra, yields
a serum which is antitoxic towards that venom; but
the great difficulty resides in the specificity of the
different poisons, which often renders the use of the
serum ineffective in countries like India and Australia,
where several kinds of poisonous snakes occur in the
same district (see above, p. <a href='#Page_67'>67</a>). In India, where a
special laboratory has been established for the supply
of antivenine, at the Central Institute of Kasauli, it
has been found impossible to obtain any venoms but
those of the Cobra and Russell’s Viper in sufficient
quantity to immunize animals, and thus produce the
serum necessary for dealing with the bite of the
King Cobra, the Krait, and the Echis Viper.</p>

<p class='c032'>In Pondicherry the French Government places
annually a sum of 200 rupees at the disposal of the
director of the hospital for obtaining Cobra poison,
the snakes, to be brought alive, being paid for to the
natives at the rate of half a rupee to one rupee each,
according to size and condition. Six hundred and
fifty-three specimens were thus purchased in less
than two years (1901-1903). The poison is utilized
for the preparation of Calmette’s antivenine, which,
as we have said above, is only effective against cobra
poison, and, unfortunately, useless for the cure of
bites from other species.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_135' id='Page_135'>135</a></span>
In Brazil, where the number of accidents is estimated
at 19,200 per annum, and that of fatal cases
at 4,800, over 2,000 snakes (<i>Lachesis</i> and <i>Crotalus</i>) are
brought annually to the Serotherapic Institute of
Batantan, in the province of S. Paolo, for the preparation
of the antitoxic serum, which is given in
exchange for the snakes. According to the latest
report of the Institute (1911), two serums are distributed:
the anti-crotaline (for Rattlesnake bite)
and the anti-bothropine (for Lachesis bite); the
third, the anti-elapine (for Coral-snake bite), is in
course of preparation.</p>

<p class='c032'>In many countries a premium has for years been
paid for the heads of poisonous snakes, and has led
to the destruction of enormous numbers of them,
without, however, resulting in a very appreciable
diminution of the dangerous reptiles. More than
£12,000 has been spent for this purpose in India alone;
the numbers destroyed in 1885 and 1886 throughout
British India amount to 420,044 and 417,596 respectively.
About forty years ago the Governor of St.
Lucia offered a reward of 4d. for every Fer-de-Lance’s
head. But the negroes caught them alive and bred
families of snakes for the sake of the reward, and
thereby made what was for them a little fortune, these
snakes bringing forth up to sixty young at a birth.
The reward had to be abolished very soon.</p>

<p class='c032'>Now about the Vipers of Europe, the only really
dangerous snakes of this part of the world.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_136' id='Page_136'>136</a></span>
Although the Adder, <i>Vipera berus</i>, is quite common
in many parts of England and Scotland, accidents
caused by its bite are rarely heard of, and cases of
death are few and far between. It is not so, however,
on the Continent, where the same species, and
especially its close ally, the more southern <i>V. aspis</i>,
are responsible for many fatalities, due no doubt to
the more virulent action of the venom in a warmer
climate.</p>

<p class='c032'>In the French Departments Loire-Inférieure and
Vendée, where these snakes are very plentiful, three
or four cases of death are reported annually. From
1860 to 1868, 370 serious accidents to man have been
carefully recorded, 53 ending in death, not only in
the case of children, but also of adults of all ages,
in 10 cases within one to twenty-four hours. In
the Puy-de-Dôme cases of death are of frequent
occurrence. In Germany and in Switzerland, 12 or
13 per cent. of the cases on record have ended fatally.
Instances of death from the bite of the south-eastern
<i>V. ammodytes</i> are also not infrequent. On the other
hand, the bite of <i>V. ursinii</i>, which is but seldom
inflicted, is not known to have ever resulted in death.</p>

<p class='c032'>It must be borne in mind that accidents are much
more frequent in districts where the poorer classes
are in the habit of going about barefoot.</p>

<p class='c032'>Anyhow, it is certain that Vipers are a serious danger
in many parts of Europe, not only to man, but also
to horses, cattle, and dogs. And it is not surprising
<span class='pagenum'><a name='Page_137' id='Page_137'>137</a></span>
that efforts have been made to reduce their numbers.
The most efficacious means, besides the protection
of certain animals and birds which feed on Vipers,
appeared to be the institution of premiums to be
paid for the heads of the dangerous snakes. By
offering
2<span class='nom'>1</span>⁄<span class='dem'>2</span>d.
per head, 500,000 Vipers (<i>V. aspis</i>) were
destroyed from 1864 to 1890 in three French departments,
Haute-Saône, Doubs, and Jura, and in one
district (Chaumont) of the Haute-Marne 57,045 were
killed from 1856 to 1861; this gives an idea of the
extraordinary abundance of these snakes in some
parts of France. In the Puy-de-Dôme the premium
was fixed for a time at 5d., and one man managed to
destroy in the course of seven years 9,175 Vipers
(<i>V. berus</i> and <i>V. aspis</i>). A woman in the Deux-Sèvres
has made a living for many years by catching
Vipers, the heads of which were paid to her at the
rate of 5d. each. The average number of her captures
amounted to 2,062 per annum (mostly <i>V. aspis</i>).
Around Oesnitz in Saxony, 2,140 <i>V. berus</i> were killed
in 1889, and 3,335 in 1890. In a single district in
Southern Styria the heads of 4,197 <i>V. berus</i> and
7,381 <i>V. ammodytes</i> were sent in for the reward in
the course of two years (1892, 1893).</p>

<p class='c032'>In spite of all this effort, the institution of the
bounty has not answered expectations, and, with
the exception of a few districts, Vipers remain as
plentiful as ever, showing what little man can do in
altering the equilibrium of Nature, except by interfering
<span class='pagenum'><a name='Page_138' id='Page_138'>138</a></span>
with the natural conditions under which
animals live. Cultivation of the ground or destruction
by fire of the vegetation of the wilderness seems
to be the only efficacious means of getting rid of so
abundant and prolific a creature as the Viper.</p>

<p class='c032'>A word may be said, however, in defence of
Vipers: they do a great deal of good to agriculture
by the destruction of small rodents, on which they
feed chiefly, and whose multiplication they serve to
keep in check. It must be pointed out that, with the
exception of the species of <i>Coluber</i> and <i>Zamenis</i>, other
European snakes are to be regarded as indirectly
injurious to agriculture, feeding as they do mainly on
lizards or frogs and toads, which, as insectivores,
deserve to be protected.</p>

<p class='c032'>Snakes are not of much economic value to man.
Tanned skins of Boas and Pythons are utilized for
making shoes and fancy articles, such as purses,
pocket-books, blotters, etc., and the Siamese make
the drum-heads of native drums out of the skins of
Pythons and <i>Acrochordus</i>. To say nothing of savages,
who seem to be partial to the flesh of large snakes,
the peasantry in some parts of France do not disdain
snakes as an article of food, the Grass-snake being
occasionally served in village inns under the name of
<i>Anguilles de haies</i>, or hedge-eels.</p>

<p class='c032'>Viper fat has for a long time been in request as an
ointment in the case of various affections, and much
used by quack doctors in the preparation of their
<span class='pagenum'><a name='Page_139' id='Page_139'>139</a></span>
remedies. Some forty years ago a chemist in Challans
(Vendée) collected Vipers (<i>V. aspis</i>) for medicinal
purposes, and was able to send several thousands to
Paris in the course of a few years, thus realizing a
considerable sum of money, but the demand has
gradually fallen off since.</p>

<p class='c032'>Very frequent in the past, snake-worship is still
prevalent in many parts of India, where the Cobra is
held in great veneration, and is never willingly killed
by the Hindoo. In pre-Buddhist days the gods
were represented with a canopy of five or seven
Cobras over them. The North African Cobra was
sacred to the ancient Egyptians, and is profusely
represented on the monuments and tombs; it was
also an emblem of the physical sun, and, as a sign of
royal power, along with the sun’s disc, formed part
of the headdress of all solar deities. The Greeks
and Romans also worshipped snakes, and the god of
medicine is represented holding a snake, which is
supposed to be <i>Coluber longissimus</i>, the so-called
“Æsculapian snake”; the occurrence at the present
day of certain common Italian species (<i>Zamenis
gemonensis</i>, <i>Coluber longissimus</i>, <i>Tropidonotus tessellatus</i>)
in isolated localities of Central Europe, formerly
Roman settlements, has been attributed to their
importation for use in the temples.</p>

<p class='c032'>Snake-charmers have existed from the remotest
antiquity, and are still to be found among all races
of men, from the accomplished Indian juggler down
<span class='pagenum'><a name='Page_140' id='Page_140'>140</a></span>
to the more commonplace European snake-catcher,
who boasts of his immunity, and of his art of attracting
snakes by devices of which he has the secret.
The Libyan Psillii of the ancient Romans have
handed down their art to the present day, and their
performances are to be witnessed in most of the
towns of Egypt and Tunisia. But India above all
lands is reputed for its snake-charmers, and the
favourite species used by them is the Cobra, which,
by the way in which it raises the anterior part of the
body and expands the region behind the head, lends
itself better than any other to the display. Constantly
facing the man before him, and swaying the
raised anterior part of the body, it seems to dance
to the music performed by the snake-man, people
believing it to be charmed by the sounds of the
instrument. However, anyone sitting on the ground
in front of a Cobra, and swaying the body from side
to side as does the man, can obtain the same result
without the aid of any sort of music.</p>

<p class='c032'>The most puzzling thing about these performances
is how the man can thus play with impunity with so
deadly a snake. It is a mistake to think that the
snake is rendered harmless through the poison fangs
having been extracted, although this subterfuge is
frequently resorted to by the less accomplished
jugglers. The immunity of the snake-charmer is to
be explained by the fact that the man has submitted
himself to a series of successive and graduated inoculations
<span class='pagenum'><a name='Page_141' id='Page_141'>141</a></span>
of the venom, a process similar to vaccination,
which renders his blood proof against the
venom of the particular species of snake, and that
one only, used for his performances.</p>

<p class='c032'>Another deadly snake shown by the snake-charmers
in North Africa is the Horned Viper,
<i>Cerastes cornutus</i>. The presence of an erect spike
above the eye is, however, not a constant character in
this snake, and hornless specimens are made to look
more formidable by spines of the hedgehog being
inserted in the proper place; the illusion is such
that even naturalists have been deceived by this
trick.</p>

<p class='c032'>Indian snake-charmers profess to have a belief in
the efficacy of snake-stones, or bezoar stones, as
a remedy to be applied on the part bitten by a
poisonous snake, a belief shared by the natives of
many tropical countries. These stones, extracted
from various reptiles, birds, and mammals, are
calcareous concretions from the stomach or bladder,
sometimes composed of superphosphate of lime, sometimes
of phosphate of ammonia or magnesia. The
value of a bezoar stone being supposed to increase
with its size, the larger are sold in India at very high
prices.</p>

<p class='c032'>In many places a popular belief prevails that such
stones are found in the heads of snakes. Mr. J. A.
Bucknill, now Attorney-General at Hong-Kong, who
spent five years in Cyprus, has informed the author
<span class='pagenum'><a name='Page_142' id='Page_142'>142</a></span>
that the Viper of the latter island, <i>Vipera lebetina</i>, is
commonly believed to contain a stone which, when
applied to the bite of a poisonous snake, quickly
nullifies the effect; it is also believed that, when this
stone is allowed to stand in a glass of water and the
water is drunk, it endows the drinker with surprising
virility. Indeed, there was an action tried by the
English judge at Larnaka in which the plaintiff
claimed the return, or damages for the non-return,
of one of these “Viper-stones” which he had lent
for a monetary consideration to the defendant for
the promotion of his manly vigour, and Mr. Bucknill’s
recollection is that the plaintiff recovered £10
for the loss.</p>
<div class='pbb'></div>
<hr class='pb' />

<div class='nf-center-c0'>
<div class='nf-center c037'  >

<span class='pagenum'><a name='Page_143' id='Page_143'>143</a></span>
SYSTEMATIC ACCOUNT OF THE SNAKES OF EUROPE<a id='r1'/><a href='#f1' class='c038'><sup>[1]</sup></a>
  </div>
</div>

<div class='chapter'>
  <h2 id='fa01' class='c014'><span class='sc'>First Family</span>: TYPHLOPIDÆ</h2>
</div>
<p class='drop-capa c033'    >Skull compact, with short, toothless lower jaw,
without transverse bone; palatine and pterygoid
reduced and toothless; maxillary small, loosely
attached to lower surface of cranium and bearing a
few small teeth; no supratemporal, the quadrate
articulated to the proötic; a coronoid element in the
lower jaw. Rudiments of a pelvic arch, reduced to
a single bone. Body vermiform, covered with uniform
cycloid scales; head small, not distinct from the
body; mouth small, crescentic, inferior; eyes under
the more or less transparent head-shields, sometimes
entirely hidden. Worm-like, smooth, shiny snakes,
of small or very small size, the largest measuring
little over 2 feet, of subterranean habits, or found in
rotten trees, under stones, or in the saw-dust of sawmills;
rarely appearing on the surface except when
the ground is soaked by heavy rains.</p>

<p class='c032'>Inhabit the intertropical parts of the whole world,
as well as South Africa, Southern Asia, and Southern
<span class='pagenum'><a name='Page_144' id='Page_144'>144</a></span>
Australia. One species occurs in South-Eastern
Europe. About 120 species are known.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus</span> TYPHLOPS, <span class='sc'>Schneider</span>
  </div>
</div>

<p class='c032'>Head with large shields; nostril in a single or
divided nasal. Tail extremely short.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    1. <span class='sc'>Typhlops vermicularis</span>, Merrem<br />
    The Greek Blind-Snake
  </div>
</div>

<p><a id='f14' name='f14' href='#f14'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_157.jpg' width="400" height="169"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 14</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Form.</i>—Slender, worm-like, the greatest diameter
of the body 40 to 52 times in the total length. Tail
about as long as broad, ending in a short spine.
Snout depressed, rounded, strongly projecting. Eyes
distinguishable, appearing as a small black spot
surrounded by an unpigmented circle; nostrils
lateral.</p>

<p class='c032'><i>Head-Shields.</i>—Rostral about one-third, or a little
less than one-third, the width of the head, extending
on its upper surface nearly to the level of the
eyes. Nasal incompletely divided, the cleft proceeding
from the second labial. Preocular present,
about as broad as the ocular, in contact with the
second and third labials. Upper head-scales feebly
enlarged and subequal. Four upper labials.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p01'><i>PLATE I</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_158a.jpg' width="400" height="151"
    alt=""/>

<p class='caption'>TYPHLOPS VERMICULARIS<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_158b.jpg' width="400" height="247"
    alt=""/>

<p class='caption'>ERYX JACULUS<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'>
<span class='pagenum'><a name='Page_145' id='Page_145'>145</a></span>
<i>Scales.</i>—Equal, 22 or 24 round the body.</p>

<p class='c032'><i>Coloration.</i>—Brown or yellowish-brown above,
yellowish beneath.</p>

<p class='c032'><i>Total Length.</i>—10 inches. A specimen from Cyprus
is reported to measure 14 inches.</p>

<p class='c032'><i>Distribution.</i>—This species has long been known
from Greece, the Ionian Islands, and the Grecian
Archipelago. It is on record from the Eli-Deren
Pass, in Bulgaria. A specimen stated to come from
Constantinople is preserved in the British Museum.
The range further extends over a considerable part of
South-Western Asia, viz., Asia Minor, Syria, Cyprus,
Transcaucasia, Persia, Turkestan, and Afghanistan.</p>

<p class='c032'><i>Habits.</i>—Pretty alert in its movements, this little
snake has considerable constricting powers, and coils
itself fast round the fingers when handled. It lives
much after the manner of earth-worms, and if dug
out of loam or sand a specimen must be instantly
grasped, as it draws back with extraordinary quickness.
Its food probably consists mainly of earthworms
and small insects. Some exotic species of
the genus are known to feed on termites, and are often
dug out of their nests.</p>

<p class='c032'><i>Reproduction.</i>—No observations have been made
<span class='pagenum'><a name='Page_146' id='Page_146'>146</a></span>
that I am aware of, but, as some of the exotic species
of which we know something more lay large, elongate
eggs, it is probable that this species also is
oviparous.</p>

<div class='chapter'>
  <h2 id='fa02' class='c014'><span class='sc'>Second Family</span>: BOIDÆ</h2>
</div>

<p class='c041'>Maxillary, palatine, and pterygoid bones movable;
transverse bone present; pterygoid extending to
quadrate or mandible; supratemporal present, attached
scale-like to cranium, suspending quadrate;
prefrontal in contact with nasal; a coronoid element
in the lower jaw. Teeth in both jaws. Vestiges of
pelvis and hind limbs, usually terminating, at least
in males, in a claw-like horny spur on each side of
the vent.</p>

<p class='c032'>This family contains, besides the gigantic Boas
and Pythons, several small more or less burrowing
forms, among which the genus <i>Eryx</i>, its only
European representative, belonging to the subfamily
Boinæ, characterized by the absence of a
supratemporal bone and of premaxillary teeth.
This subfamily, the largest members of which inhabit
tropical America, is distributed over the hotter
parts of America, Asia west of the Bay of Bengal,
Madagascar, the Mascarene Islands, Africa north of
the equator, Papuasia, and some islands of the South
Pacific. The habitat of the European species is
confined to the eastern and southern countries of
the Mediterranean district.</p>

<p class='c032'>This very varied family, including terrestrial,
<span class='pagenum'><a name='Page_147' id='Page_147'>147</a></span>
arboreal, aquatic, and burrowing forms, is a comparatively
small one as regards the number of species,
viz., about sixty, of which one-third pertain to the
Pythoninæ, which inhabit tropical and South Africa,
Southern Asia, Papuasia, Australia, and Mexico.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus</span> ERYX, <span class='sc'>Daudin</span>
  </div>
</div>

<p class='c032'>Anterior maxillary and mandibular teeth longer
than the posterior. Head small, not distinct from
neck, covered with small scales; a large rostral
shield. Eye very small, with vertical pupil. Body
cylindrical; scales small; ventral shields narrow.
Tail very short; subcaudal shields mostly single.</p>

<p class='c032'>The range of this genus, embracing eight species,
extends from South-Eastern Europe and Africa north
of the equator to Central Asia and India.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    2. <span class='sc'>Eryx jaculus</span>, Linnæus<br />
    The Javelin Sand-Boa
  </div>
</div>

<p class='c032'><i>Form.</i>—Stout. Head small, not distinct from
neck; snout projecting beyond the mouth; eye
directed upwards and outwards; a feeble mental
groove. Tail, ending very obtusely, one-tenth to
one-sixteenth of the total length. Anal spurs more
or less developed, often absent in the female.</p>

<p class='c032'><i>Head-Shields.</i>—Rostral very large and broad, with
angular horizontal edge, followed by a pair of internasals
and a second row of two or three small shields,
<span class='pagenum'><a name='Page_148' id='Page_148'>148</a></span>
the rest of the upper surface of the head covered with
scale-like shields, 5 to 8 from eye to eye across the
vertex, 7 to 11 round the eye; 9 to 12 upper labials,
second or third deepest, separated from the eye by
one or two series of scales. Nostril between the
internasal and two nasals, the anterior of which
sometimes fuses with the former. Two or three
series of scales between the nasals and the eye.</p>

<p><a id='f15' name='f15' href='#f15'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_163.jpg' width="400" height="187"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 15</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Scales.</i>—Smooth, feebly keeled on the posterior
part of the body and on the tail, in 40 to 51 rows.
Ventrals narrow, occupying about one-third of the
ventral surface, 163 to 200; anal small, entire; subcaudals
all or greater part single, 15 to 29.</p>

<p class='c032'><i>Coloration.</i>—Pale greyish, reddish, or yellowish-brown
above, with brown, purplish-brown, or blackish
markings, which may be very irregular or form a
single or alternating series of large blotches or cross-bands
on the back; the sides with smaller spots;
these markings may be confluent and so large as to
<span class='pagenum'><a name='Page_149' id='Page_149'>149</a></span>
reduce the ground colour to small yellowish spots;
one, two, or three short, dark stripes often present on
the nape; a dark streak from the eye to the angle of
the mouth; sometimes a dark curved band from eye
to eye across the upper surface of the snout. Lower
parts yellowish-white, uniform or with small blackish
spots.</p>

<p class='c032'><i>Size.</i>—2<span class='nom'>1</span>⁄<span class='dem'>4</span>
feet is the greatest length which this
snake is known to attain.</p>

<p class='c032'><i>Distribution.</i>—Originally described from Lower
Egypt, and extending westwards to Algeria, this
<i>Eryx</i> has been found in Greece, in Corfu, in the
Cyclades, in Turkey, and in Roumania. It occurs
also in Asia Minor, in Transcaucasia, in Transcaspia,
in Northern Persia, and in Syria. It has
been found at an altitude of 5,000 feet in Persia, to
the west of Lake Urmia. A closely allied form
(<i>E. miliaris</i>, Pallas), which has been confounded with
this species, extends from Transcaspia to Turkestan
and Afghanistan.</p>

<p class='c032'>The reported occurrence of this snake in Bulgaria
is based on a specimen labelled “Bulgaria (?)” in the
Sofia University Museum. The species is omitted
from Kovatscheff’s latest list of Bulgarian Reptiles.</p>

<p class='c032'><i>Habits.</i>—This diminutive Boid is a burrower in
arid, sandy districts, appearing only early in the
morning or towards dusk; it is as a rule more
crepuscular than nocturnal. Notwithstanding its
rather heavy form, it is capable of very quick movements,
<span class='pagenum'><a name='Page_150' id='Page_150'>150</a></span>
darting like an arrow upon its prey, which
consists chiefly of small mammals and lizards. A
constrictor, like all the members of the family to
which it pertains, it crushes its prey before swallowing
it. If given several mice at a time, it will catch and
kill them all in succession before proceeding to feed.
Specimens recently discovered in the Danube Valley
in Roumania were found to live in the sand at the
bottom of small limestone caves, going about at
night and feeding principally on slugs. Unlike other
snakes, it is said to lap dewdrops with its tongue.
It is a gentle snake, seldom attempting to bite.</p>

<p class='c032'>Egyptian jugglers are in the habit of implanting
the claw of a bird or small mammal in the skin of
the head of this snake, above each eye, in order to
give it a more formidable appearance.</p>

<p class='c032'><i>Reproduction.</i>—Like the other species of <i>Eryx</i>, this
snake is ovoviviparous, but, beyond this fact, nothing
appears to have been observed concerning the breeding
habits, although many examples have been kept
in captivity.</p>

<div class='chapter'>
  <h2 id='fa03' class='c003'><span class='sc'>Third Family</span>: COLUBRIDÆ</h2>
</div>

<p class='c041'>Maxillary, palatine, and pterygoid bones movable;
transverse bone present; pterygoid extending to
quadrate or mandible; supratemporal present, attached
scale-like to cranium, suspending quadrate;
prefrontal not in contact with nasal; maxillary
horizontal, not movable perpendicularly to the transverse
<span class='pagenum'><a name='Page_151' id='Page_151'>151</a></span>
bone; no coronoid bone. Teeth in both jaws.
No vestiges of pelvic arch.</p>

<p class='c032'>An enormous group, comprising the great majority
of snakes. Divided into three parallel series:</p>

<p class='c032'><i>A.</i> Aglypha, with all the teeth solid.</p>

<p class='c032'><i>B.</i> Opisthoglypha, with one or more of the posterior
maxillary teeth grooved.</p>

<p class='c032'><i>C.</i> Proteroglypha, with the anterior maxillary teeth
grooved or canaliculated.</p>

<p class='c032'>The third, which is not represented in Europe,
includes some of the most deadly snakes, such as the
Cobras, Kraits, Death-adders, etc.</p>

<p class='c032'>The European genera are thus distributed in the
two other series:</p>

<p class='c032'><span class='sc'>Aglypha</span> (<span class='sc'>Colubrinæ</span>): <i>Tropidonotus</i>, <i>Zamenis</i>,
<i>Coluber</i>, <i>Coronella</i>, <i>Contia</i>.</p>

<p class='c032'><span class='sc'>Opisthoglypha</span> (<span class='sc'>Dipsadomorphinæ</span>): <i>Cœlopeltis</i>,
<i>Macroprotodon</i>, <i>Tarbophis</i>.</p>

<p class='c032'>These genera give but a feeble idea of the
variety of forms included in this family, which
comprises adaptations to every mode of life for which
snakes are fitted.</p>

<p class='c032'>The distribution of the family coincides with that
of the order, extending over the whole world with
the exception of the Arctic and Antarctic regions,
and Ireland and New Zealand, as well as most of
the smaller islands of the Pacific Ocean.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >

<span class='pagenum'><a name='Page_152' id='Page_152'>152</a></span>
<span class='sc'>Genus</span> TROPIDONOTUS, <span class='sc'>Kuhl</span>
  </div>
</div>

<p class='c032'>Maxillary teeth increasing in size posteriorly.
Head more or less distinct from neck; eye moderate
or rather small, with round pupil. Body more or
less elongate; scales keeled, with apical pits. Tail
moderate.</p>

<p class='c032'>This large genus, comprising about ninety species,
and of almost cosmopolitan distribution, with the
exception of South America and the greater part of
Australia, may be divided into several subgenera, two
of which are represented in Europe—<i>Tropidonotus</i>
proper, with the common <i>T. natrix</i>, and <i>Nerodia</i>,
Baird and Girard, with two closely related species
of more thoroughly aquatic habits, <i>T. tessellatus</i> and
<i>T. viperinus</i>.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    3. <span class='sc'>Tropidonotus natrix</span>, Linnæus<br />
    (<i>Natrix vulgaris</i>, Laurenti; <i>Coluber torquatus</i>, Lacepède)<br />
    The Grass-Snake, or Ring-Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Moderately slender; snout short, obtuse,
not prominent; eyes and nostrils lateral, the former
moderately large. Tail four to six and a half times
in the total length.</p>

<p class='c032'><i>Head-Shields.</i>—Rostral broader than deep, visible
from above. Nasal divided, very rarely semidivided.
Internasals at least as broad as long, trapezoid,
shorter than the prefrontals. Frontal broader than
<span class='pagenum'><a name='Page_153' id='Page_153'>153</a></span>
the supraocular, once and one-third to once and a half
as long as broad, as long as or a little shorter than
its distance from the end of the snout, shorter than
the parietals, not in contact with the preocular.
Loreal deeper than long. One (rarely two) pre-
and three (rarely two or four) postoculars. Temporals
1 + 2. Upper labials seven (rarely six or
eight), third and fourth (or fourth and fifth) entering
the eye. Four or five lower labials in contact with
the anterior
chin-shields,
which are
shorter than
the posterior.</p>

<p class='c032'><i>Scales</i> with
two apical
pits, in nineteen
rows,
strongly
keeled on the body, of outer row smooth or faintly
keeled. Ventral shields 157 to 181; anal divided;
subcaudals 50 to 88.</p>

<p><a id='f16' name='f16' href='#f16'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_168.jpg' width="200" height="130"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 16</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Coloration.</i>—Very variable. We shall first describe
the typical form, and then allude to the
principal varieties and individual variations with
which we are acquainted.</p>

<p class='c032'>Grey, bluish-grey, olive, or brown, above, usually
with black spots or narrow bars on the back, and
vertical bars on the sides; upper lip whitish or
<span class='pagenum'><a name='Page_154' id='Page_154'>154</a></span>
yellowish, with the sutures between the shields black;
the preocular, and sometimes the postoculars, yellow
in the young; a white, yellow, or orange collar on the
nape, sometimes uninterrupted, more often divided
in the middle, bordered behind by two black subtriangular
or crescentic blotches, which usually meet
on the median line; the bright collar often becomes
faint, or even entirely disappears, in large females
(<a href='#p02'>Plate II</a>., first figure); belly usually checkered black
and grey or white, more rarely grey with small black
spots, or entirely black. Iris dark brown or reddish-brown,
with a golden circle round the pupil. This
is the form found in England and Central Europe
and in some parts of Southern Europe.</p>

<p class='c032'>In Jersey, in the Spanish Peninsula, and in
Cyprus, the white or yellow collar, which is always
present in the very young, soon disappears, and so
does usually the black collar, which is either much
reduced or entirely absent (var. <i>astreptophorus</i>,
Seoane). Some large specimens from the Spanish
Peninsula are uniform olive, without any markings.</p>

<p class='c032'>Another variation (<a href='#p02'>Plate II</a>., third figure), rare in
France, but common in Italy, South-Eastern Europe,
and Asia Minor (var. <i>persa</i>, Pallas; <i>bilineatus</i>, Bibr.;
<i>murorum</i>, Bonap.) has the collar well marked, though
widely interrupted in the middle, and a white, yellow,
or orange streak extends along each side of the back,
which may bear the usual black markings in addition.</p>

<p class='c032'>In some specimens from Austria and Corfu (var.
<span class='pagenum'><a name='Page_155' id='Page_155'>155</a></span>
<i>subfasciatus</i>, Werner) the belly is white, with black
bars occupying the free edge of each ventral shield.</p>

<p class='c032'>A very remarkable variety (var. <i>cettii</i>, Gené) from
Corsica and Sardinia (<a href='#p02'>Plate II</a>., second figure) is grey
or olive above, with the black markings confluent
into more or less regular annuli, which are nearly
as wide as the spaces between them; these annuli
are often broken up on the middle line of the back,
and alternating; the collar is absent, or is transformed
into the first annulus, and the upper surface
of the head is more or less spotted or blotched with
black. This pattern is most distinct in young and
half-grown specimens; in large examples the annuli
may break up into spots, disposed with great symmetry
in transverse series. The belly is black,
spotted with white.</p>

<p class='c032'>A specimen 20 inches long, from Bona, Algeria
(Lataste collection), has the posterior half of the
head, from between the eyes and behind the postocular
shields, of an intense black, followed by the
usual yellow and black collar; two light dots close
together on the parietal shields.</p>

<p class='c032'>Some specimens are entirely or nearly entirely
black. In the var. <i>picturatus</i>, Jan, from the Caucasus,
the upper parts are sprinkled all over with light
dots, and the yellow collar is present; the belly is
grey, dotted with black, and with white spots on
the sides. In others the body is black above, and
checkered black and white beneath (var. <i>scutatus</i>,
<span class='pagenum'><a name='Page_156' id='Page_156'>156</a></span>
Pall.), or entirely black (var. <i>ater</i>, Eichw.). This
melanism never appears until the second or third
year of life, the young being marked like the typical
form.</p>

<p class='c032'>Albinos have occasionally been met with, yellowish
flesh-colour with reddish markings, and a white or
yellow collar, the eye and the tongue red. Such an
albino, from Horsted Keynes, Sussex, is preserved
in the British Museum. A remarkable aberration, to
be regarded as an imperfect albino, has been found
in Dorsetshire, and described as uniform whitish,
with a well-defined broad longitudinal central dorsal
pale yellow-brown band.</p>

<p class='c032'><i>Size.</i>—May reach a length of 6 feet 8 inches.
Such giants, females, known from Sardinia, Sicily,
and Istria, are, however, very exceptional, individuals
of this species seldom exceeding a length of 4 feet.
The largest British specimen on record, from Wales,
is stated to measure 5 feet 10 inches. Males rarely
exceed 3 feet.</p>

<p class='c032'><i>Monstrosity.</i>—A dicephalous young, with the two
well-formed heads side by side, is preserved in the
British Museum, and several others have been
described, one being reported to have lived for
about a month.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p02'><i>PLATE II</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_172a.jpg' width="400" height="90"
    alt=""/>
<p class='caption'>TROPIDONOTUS NATRIX<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_172b.jpg' width="400" height="230"
    alt=""/>
<p class='caption'>T. NATRIX, VAR. CETTII<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_172c.jpg' width="400" height="108"
    alt=""/>
<p class='caption'>T. NATRIX, VAR. PERSA</p>
</div>

<p class='c032'><i>Distribution.</i>—<i>Tropidonotus natrix</i> occurs all over
Europe, with, of course, the exception of Ireland,
as far north as the extreme south-east of Scotland,
and the
sixty-fifth degree in Scandinavia and Finland,
<span class='pagenum'><a name='Page_157' id='Page_157'>157</a></span>
and as high up as 7,450 feet in the Italian Alps.
With the exception of a few districts in England and
in Central Europe, as well as in the extreme north,
it is common everywhere, in the north as well as
in the south. On the Mediterranean islands it is
absent from the Baleares and Malta. In North
Africa it is known from Algeria and Tunisia, north
of the Atlas, where it does not seem, however, to
be at all common. It has a wide range in Asia,
extending eastwards to Lake Baikal, and southwards
to Cyprus, Asia Minor, and Northern Persia. In
the south-east of its range, the bilineated variety
predominates over the typical form. The melanistic
so-called varieties are not geographically restricted,
but occur all over the habitat of the species, though
not recorded from England.</p>

<p class='c032'><i>Habits.</i>—Although fond of water, and often seen
swimming in ponds or streams or creeping by the
water’s edge, this snake is far less aquatic than its
two congeners described hereafter; it often occurs
on dry chalk hills or in woods far from any water.
It is moderately agile in its movements, and easily
caught, on which occasions it hisses loudly and
emits a nauseous smell from its anal glands, together
with the renal dejections, but makes no attempt to
bite; exceptionally an individual may go so far as
to strike with open mouth, but cases of this snake
really biting are extremely rare. However, Gené
says of the male of his <i>Natrix cettii</i>, “iracundum et
<span class='pagenum'><a name='Page_158' id='Page_158'>158</a></span>
mordacissimum animal.” Dr. Gadow relates his
experience with aggressive specimens which inhabited
a swamp with a little stream to the north
of Oporto, close to the coast. To his utter surprise,
some of them actually made for him, swimming
along rapidly with the head erect, about 6 inches
above the water, and darting forwards with widely
opened jaws; but they did not bite. According to
Professor Kathariner, this snake when caught has
been observed to sham death, lying rigid and motionless,
with open gape. Some specimens do well in
captivity, and are known to have lived for many
years; others refuse all food and die of starvation.
After a time they become tolerably tame, and cease
to produce the offensive odour when handled.</p>

<p class='c032'>The food consists of frogs and toads—the latter
being preferred notwithstanding their poisonous
secretion, which protects them from the attacks of
most animals—occasionally of newts, seldom of fish;
these snakes are reported to have a predilection for
tree-frogs, and to feed occasionally on mice and birds,
but most observers agree that they will not take
anything higher in the zoological scale than frogs.
The prey is swallowed alive, and, if not very large,
four or five frogs or toads are often taken in succession;
a case is known of a snake having swallowed
twenty very small frogs at one meal. The young
feed on worms and batrachian larvæ, in addition
to very small frogs and toads.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_159' id='Page_159'>159</a></span>
The Grass-snake gets on very well with the
Adder, to whose venom it is immune.</p>

<p class='c032'>It has more than once been met with swimming
in the sea, and a case is reported of one having been
captured in the open sea twenty-five miles from the
nearest land, no doubt carried away by the current,
but still perfectly lively.</p>

<p class='c032'>The hibernating season is spent in holes in walls
or at the root of trees, often under manure-heaps,
and the awakening occurs in March or April, soon to
be followed by the first exuviation and the pairing.</p>

<p class='c032'><i>Reproduction.</i>—Pairing takes place in April or in
May, according to the climate, and the eggs are
laid between June and August, the young emerging
six to ten weeks later. It is probable that a second
pairing occasionally takes place in the autumn, as
eggs have sometimes been found in manure-heaps
at the end of winter. Females do not breed until
about 2 feet long, males a little sooner. The eggs
number 11 to 48, according to the size of the
female, and, after being produced in a string, stick
together in a mass, without any regularity.</p>

<p class='c032'>The eggs measure 1 to
1<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches in length, and
when newly laid are about once and a half as long
as broad. They often contain at the time they are
produced a more or less developed embryo. They
are sometimes laid in recesses in walls, in heaps
of sawdust near sawmills, under dead leaves, but
preferably in manure, for which purpose females
<span class='pagenum'><a name='Page_160' id='Page_160'>160</a></span>
often approach farms during the period of oviposition.
Holes near baking ovens at the back of village houses
are sometimes selected as breeding resorts. The
female rolls herself up, and by violent contortions
makes a sort of chamber in the manure, in which
she may remain for some days after the eggs have
been produced. It is not very unusual for several
females to congregate for the purpose of laying, and
as many as 1,200 eggs have been found in the same
hole. The young on emerging has lost the umbilical
cord, and measures 6 to
8<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches. It often
remains for a considerable time, sometimes until
the following spring, in the hole or manure-heap in
which it was born, feeding principally on worms.
Very young specimens are never found in the water.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    4. <span class='sc'>Tropidonotus tessellatus</span>, Laurenti<br />
    (<i>Coluber hydrus</i>, Pallas)<br />
    The Tessellated Water-Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Rather slender; head rather long and
narrow; snout obtuse, not prominent; eyes and
nostrils directed upwards and outwards, the former
rather small, the latter somewhat valvular. Tail
four to six times in the total length.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p03'><i>PLATE III</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_178a.jpg' width="400" height="80"
    alt=""/>
<p class='caption'>TROPIDONOTUS TESSELLATUS</p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_178b.jpg' width="400" height="71"
    alt=""/>
<p class='caption'>TROPIDONOTUS VIPERINUS<br />
<i>After Sordelli</i></p>
</div>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_178c.jpg' width="400" height="155"
    alt=""/>
<p class='caption'>T. VIPERINUS, VAR. AUROLINEATUS<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral broader than deep, visible
from above. Nasal often semidivided. Internasals
usually as long as broad or longer, subtriangular,
truncate in front, as long or nearly as long as the
<span class='pagenum'><a name='Page_161' id='Page_161'>161</a></span>
prefrontals. Frontal a little broader than the supraocular,
once and a half to twice as long as broad, as
long as or a little shorter than its distance from the
end of the snout, shorter than the parietals, not in
contact with the preocular. Loreal as deep as or
deeper than long. Two (rarely one or three) preoculars,
with or without a small subocular below;
three postoculars, often with one or two suboculars
below. Temporals 1 + 2. Upper labials eight (rarely
seven, nine, or
ten), fourth or
fourth and fifth
(rarely third or
fifth) entering
the eye. Five
(rarely four)
lower labials in
contact with the
anterior chin-shields,
which are shorter than the posterior.</p>

<p><a id='f17' name='f17' href='#f17'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_180.jpg' width="200" height="137"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 17</span></p>
</div>

<p class='c032'><i>Scales</i> with two apical pits, in nineteen rows,
strongly keeled, of outer row smooth or feebly keeled.
Ventrals 160 to 187; anal divided; subcaudals
48 to 79.</p>

<p class='c032'><i>Coloration.</i>—Olive, olive-grey, or brown above, with
dark spots usually arranged quincuncially or forming
narrow bars on the back (<a href='#p03'>Plate III</a>.); sides often with
lighter vertical bars; a more or less distinct
<b>Λ</b>-shaped
dark band on the nape, sometimes produced as a
<span class='pagenum'><a name='Page_162' id='Page_162'>162</a></span>
median streak to the frontal shield; upper lip
yellowish, with dark bars on the sutures between the
shields. Lower parts whitish, yellow, orange, or
red, marbled or checkered with black, or nearly
entirely black. Iris golden, bronzy, or coppery red.</p>

<p class='c032'>Some specimens depart very strikingly from the
coloration thus briefly defined. We will now
mention the principal variations which have been
described: Sides of body checkered with black and
yellow or black and red (var. <i>rubro-maculosus</i>,
Dürigen). With four dark stripes along the anterior
part of the back (var. <i>lineaticollis</i>, Werner). Above
with four light streaks in addition to the dark
markings. Uniform grey or light brown above (var.
<i>concolor</i>, Jan, <i>hagenbecki</i>, Werner). Uniform black or
blackish (var. <i>nigrescens</i>, De Betta). The most
remarkable variety is the var. <i>vosseleri</i>, Werner,
from Asia Minor: above with small black and
yellowish spots, beneath yellowish with three blackish
stripes beginning at some distance from the head,
the median much weaker than the outer; the scales
are less strongly keeled than in the typical form.
There are also specimens with two very regular
black stripes along the belly.</p>

<p class='c032'>A case of chlorochroism, in a specimen from Dalmatia,
has been observed by Peracca. The snake was
sulphur yellow with black markings; a black band
along the belly; iris golden.</p>

<p class='c032'>An imperfect albino, which has been met with
<span class='pagenum'><a name='Page_163' id='Page_163'>163</a></span>
several times in Dalmatia, has been described as
var. <i>flavescens</i>, Werner. Yellowish-white or brownish-yellow
above, with small blackish spots; belly
whitish in the middle, with a series of black spots,
bright yellow on the sides; eye and tongue red.</p>

<p class='c032'><i>Size.</i>—This snake occasionally reaches a length of
4 feet, but specimens over 3 feet are rare. The
largest specimen in the British Museum measures
3 feet 10 inches.</p>

<p class='c032'><i>Distribution.</i>—The Tessellated Snake has a wide
range in Europe and Asia. It is found south of the
Alps, from Liguria to Naples, and eastwards, extending
northwards over the greater part of Austria-Hungary,
and even as far as Saxony, and again reappears
to the west in various localities of the Middle
Rhine district (from Bingen to Coblenz and Kreuznach,
from Nassau to Lahnstein) and of the Moselle.
From Southern Russia it extends into Siberia as far as
the Altai, the extreme west of China, and the extreme
north-west of India; it is also found in Asia Minor,
Transcaucasia, Persia, Mesopotamia, Syria, and the
neighbouring parts of Egypt. Italy and the Rhine
constitute the western limit of its range in Europe.
It does not ascend to any considerable altitude
in the mountains of Europe, but it is on record from
6,000 feet elevation in Chitral.</p>

<p class='c032'><i>Habits.</i>—This is a far more aquatic species than
the preceding, being seldom found in summer away
from the water, in which it swims and dives to
<span class='pagenum'><a name='Page_164' id='Page_164'>164</a></span>
perfection; which does not prevent it from being
equally agile on land. In accordance with these
thoroughly aquatic habits, it feeds mostly on fish,
although occasionally taking frogs and toads and
their tadpoles. Small fish are swallowed in the
water, but large ones are landed. This snake does
not object to salt water, and it has been observed
on the seashore near Odessa, chasing small fish,
mostly gobies, in shallow water. Hibernation and
pairing take place on land, and it is not until the
latter function is accomplished that the snakes of
this species resort to the water, which the females
leave again for oviposition. Like the Grass-snake,
the Tessellated Snake seldom bites.</p>

<p class='c032'><i>Reproduction.</i>—Pairing takes place in spring, when
large numbers have been observed to congregate for
the purpose. As in the Viperine Snake, a second
pairing may occur in the autumn, Dr. Werner having
found a pair in copula on September 14, at Trebinje,
Herzegovina, the female laying her eggs in the
following July, which with the beginning of August
is the time for oviposition. The eggs measure a
little over an inch in length and two-thirds of an
inch in width, and number 5 to 25; they are deposited
under stones, in the fissures of walls and rocks, or
under the refuse of tanneries.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >

<span class='pagenum'><a name='Page_165' id='Page_165'>165</a></span>
5. <span class='sc'>Tropidonotus viperinus</span>, Latreille<br />
    The Viperine Water-Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Moderately slender; head shorter than
in the preceding species; snout obtuse, not prominent;
eyes and nostrils directed upwards and
outwards, the former rather small, the latter somewhat
valvular; tail four to six times in the total
length.</p>

<p><a id='f18' name='f18' href='#f18'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_184.jpg' width="200" height="151"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 18</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral broader than deep, visible
from above. Nasal usually semi-divided. Internasals
as long as
broad or longer,
subtriangular,
truncate in front,
as long as the prefrontals.
Frontal
usually broader
than the supraocular,
once and
a half to twice
as long as broad, as long as or slightly longer
than its distance from the end of the snout, shorter
than the parietals, not in contact with the preocular.
Loreal as deep as or a little deeper than long. One
or two preoculars and two (rarely three) postoculars.
Temporals 1 + 2 or 1 + 3. Upper labials seven (rarely
eight), third and fourth (or third, fourth, or fourth
and fifth) entering the eye. Four (rarely five) lower
<span class='pagenum'><a name='Page_166' id='Page_166'>166</a></span>
labials in contact with the anterior chin-shields,
which are usually shorter than the posterior.</p>

<p class='c032'><i>Scales</i> with two apical pits, in twenty-one (rarely
nineteen or twenty-three) rows, strongly keeled, of
outer row smooth or feebly keeled. Ventrals 147 to
164; anal divided; subcaudals 46 to 72.</p>

<p class='c032'><i>Coloration.</i>—Grey, brown, or reddish above with
two alternating series of dark brown or black spots
on the back, or with a black zigzag dorsal band
(<a href='#p03'>Plate III</a>., second figure), rarely with a single series
of black vertebral spots; a lateral series of black
spots, usually ocellar, with yellow centres; upper
surface of head with dark symmetrical markings;
a more or less distinct dark band on the temple, and
another on each side of the nape, often edged with
yellow in front; upper lip yellow, with dark bars
on the sutures between the shields, or dark with a
yellow spot on each shield. Lower parts yellow or
red, checkered with black, or entirely black; the
black of the belly may be connected with the ocellar
lateral spots by black vertical bars. Iris golden,
often mixed with brown.</p>

<p class='c032'>A specimen from Ponte Carrega, near Genoa,
preserved in the Genoa Museum, is remarkable as
being of a dark olive-grey, with three series of black
and yellow ocellar spots. It is further exceptional
in having the scales in nineteen rows. A second
specimen, from the same locality, with the normal
number of scales, has some of the vertebral spots
<span class='pagenum'><a name='Page_167' id='Page_167'>167</a></span>
ocellar. Specimens with ocellar vertebral spots are
found also in Sardinia and in Spain.</p>

<p class='c032'>As in <i>T. natrix</i>, there occur, in the South of
France, in Sardinia, in the Spanish Peninsula, and
in North Africa, specimens with two light yellow
or reddish lines along the back (<a href='#p03'>Plate III</a>., third
figure), in addition to the usual markings (<i>C. aurolineatus</i>,
Gervais, <i>T. chersoides</i>, Duméril and Bibron).</p>

<p class='c032'>Melanism is rare in this species, only one specimen
being known, from Nantes in Southern Brittany;
uniform black, with the exception of a few white
spots on the belly. A remarkable variety (var.
<i>incertus</i>, Fatio), connecting this species with the
preceding, occurs in Switzerland near Geneva. Not
only is its coloration sometimes very similar to
that of <i>T. tessellatus</i>, but it agrees with it in the scales
being often disposed in nineteen rows instead of
twenty-one, and in the presence of eight upper
labials, fourth or third and fourth entering the eye;
however, the frequent presence of ocellar spots
on the sides, and the low number of ventral shields
(147 to 151), show that it should be referred to
<i>T. viperinus</i>.</p>

<p class='c032'><i>Size.</i>—Rarely reaches a length of 3 feet in Europe,
the largest specimens being from Sardinia. An
Algerian specimen 3 feet 3 inches long is on record.</p>

<p class='c032'><i>Distribution.</i>—France as far north as Southern
Brittany, the Forest of Fontainebleau, and the
Department Aube, the whole of the Spanish Peninsula
<span class='pagenum'><a name='Page_168' id='Page_168'>168</a></span>
and the Balearic Islands, Southern Switzerland,
north and south of the Alps, Liguria, Piedmont,
Corsica, Sardinia, and Sicily. In Africa in
Morocco, Algeria, and Tunisia, penetrating into the
northern parts of the Sahara.</p>

<p class='c032'>In Liguria, Piedmont, and Ticino, <i>T. viperinus</i>
occurs alongside with <i>T. tessellatus</i>. It reaches an
altitude of nearly 4,000 feet in the Alps.</p>

<p class='c032'><i>Habits.</i>—Very much the same as in the preceding
species, although slightly less thoroughly aquatic,
large individuals being sometimes met with at some
distance from water. Ponds and marshes are the
favourite abode of the Viperine Snake, huge numbers
being often found on the borders, diving into
the water when disturbed. Frogs and toads, tadpoles,
newts, fishes, and large earthworms, are its
principal food when adult, the young feeding chiefly
on batrachian larvæ, young fishes, and earthworms.
A case is known of this snake having eaten a water-shrew
(<i>Crossopus fodiens</i>). When a fish has been
caught, it is usually eaten on land; in captivity dead
fish are rather readily accepted, provided they be
quite fresh. Some specimens bite when handled;
others are as gentle as the Grass-snake.</p>

<p class='c032'>For hibernation, hollow trees, fissures in rocks,
holes in the ground or in railway embankments,
are selected, and numerous individuals sometimes
congregate in the same retreat. In the mild winters
of the South of Europe they remain quiet, without
<span class='pagenum'><a name='Page_169' id='Page_169'>169</a></span>
being torpid, and resume activity very early in the
spring.</p>

<p class='c032'>In the Alemtejo, according to Gadow, when
during the rainless and hot summer the small rivers
have nearly dried up, these snakes collect in great
quantities in the remaining stagnant and muddy
pools, and, as the stock of suitable fish gets exhausted,
are often reduced to a deplorably emaciated
condition. By the month of August they have
become so thoroughly aquatic that they cannot be
kept alive in dry surroundings for twenty-four hours,
apparently dying from some kind of cutaneous
suffocation. The same observer once caught a
Viperine Snake in a ditch whilst it was swallowing
an eel of nearly its own length.</p>

<p class='c032'>Some specimens show so great a superficial resemblance
to the Common Adder, <i>Vipera berus</i>,
which, however, being a more northern reptile, very
seldom occurs in the same localities—that this snake
well deserves its name <i>Viperinus</i>. A celebrated
herpetologist, Constant Duméril, was once himself
deceived by this resemblance and bitten by a <i>Vipera
berus</i> which he had picked up in the Forest of Senart,
near Paris, believing it to be a <i>Tropidonotus viperinus</i>;
whilst, conversely, a specimen of the harmless snake
was killed in mistake for a Viper by no less an expert
than Dr. Viaud-Grandmarais.</p>

<p class='c032'><i>Breeding.</i>—This snake pairs in March and April,
and sometimes again in the autumn; but the eggs
<span class='pagenum'><a name='Page_170' id='Page_170'>170</a></span>
are only laid at one season, in June or July, and
hatch in August, September, or October. The eggs,
numbering four to twenty, are deposited in holes not
far from water, often in abandoned galleries of voles
or moles. The young at birth measure 4 to
6<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches, and soon resort to the water, where, unlike
those of the Grass-snake, they are frequently met
with.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus ZAMENIS, Wagler</span>
  </div>
</div>

<p class='c032'>Maxillary teeth increasing in size posteriorly, the
two last often separated from the others by a narrow
interspace. Head elongate, distinct from neck;
eye rather large, with round pupil. One or more
subocular shields. Body much elongate; scales
smooth, with apical pits. Tail long.</p>

<p class='c032'>The species of this genus, about thirty in number,
are distributed over Europe, North Africa, Asia, and
North and Central America. Three inhabit Europe.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    6. <span class='sc'>Zamenis gemonensis</span>, Laurenti<br />
    (<i>Coluber viridiflavus</i>, Lacepède; <i>C. atrovirens</i>, Shaw)<br />
    The European Whip-Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Slender; snout rounded, with distinct
canthus, moderately prominent, concave on each
side in front of the eye. Tail three and one-third
to four and one-third times in the total length.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p04'><i>PLATE IV</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_190a.jpg' width="189" height="48"
    alt=""/>
<p class='caption'>ZAMENIS GEMONENSIS<br />
<i>Young, after Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_190b.jpg' width="278" height="55"
    alt=""/>
<p class='caption'>Z. GEMONENSIS, VAR. PERSICUS<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_190c.jpg' width="400" height="76"
    alt=""/>
<p class='caption'>Z. GEMONENSIS, VAR. VIRIDIFLAVUS</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral a little broader than deep,
the portion visible from above measuring one-fourth
to two-fifths its distance from the frontal. Frontal
<span class='pagenum'><a name='Page_171' id='Page_171'>171</a></span>
more or less bell-shaped, not or but little broader
than the supraocular, once and two-thirds to twice
as long as broad, as long as or a little longer than
its distance from the end of the snout, a little
shorter than the parietals. Loreal as long as deep
or longer. One preocular (rarely two), extending to
the upper surface of the head, but never in contact
with the frontal; a small subocular below the preocular;
two postoculars (rarely three). Temporals
2 + 2 or 2 + 3
(rarely 1 + 2).
Upper labials
eight, fourth and
fifth entering the
eye, fifth and
seventh deepest.
Five lower labials
(rarely four) in
contact with the
anterior chin-shields, which are usually shorter than
the posterior.</p>

<p><a id='f19' name='f19' href='#f19'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_192.jpg' width="200" height="148"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 19</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Scales</i> with two apical pits, in nineteen (rarely
seventeen or twenty-one) rows. Ventral shields
more or less distinctly angulate laterally, 160 to 230
(usually under 200 in the typical form and the var.
<i>caspius</i>, 190 or more in the vars. <i>viridiflavus</i> and
<i>asianus</i>); anal divided; subcaudals 87 to 131.</p>

<p class='c032'><i>Coloration.</i>—In the typical <i>Z. gemonensis</i> the upper
parts are yellowish-brown or pale olive, anteriorly
<span class='pagenum'><a name='Page_172' id='Page_172'>172</a></span>
with blackish cross-bars or numerous small black
spots, the black scales with a yellowish shaft, the
lower parts yellowish-white or pale yellow, rarely
more orange; the sides of the head are yellow, the
shields edged with blackish. A female,
3<span class='nom'>1</span>⁄<span class='dem'>4</span>
feet long,
from Levico, Trentino, preserved in the Genoa
Museum, is uniform reddish-brown above, with mere
traces of darker markings on the head and nape.
There is every gradation between this form and the
var. <i>viridiflavus</i> or <i>atrovirens</i> (<a href='#p04'>Plate IV</a>., third figure),
which is dark green or black above, with yellow spots
forming transverse series or bars on the anterior
part of the body, and longitudinal streaks, following
the series of scales, on the posterior part and on the
tail; the yellow sometimes predominates over the
black, or may appear as a shaft along each dark
scale; the preocular and postocular shields are
yellow, the labials likewise yellow, with black spots
or bars. The lower parts are yellow or greenish-white,
with or without black dots, and usually with
a series of large black spots on each side.</p>

<p class='c032'>Some specimens of both the typical form and the
var. <i>viridiflavus</i> are entirely black or nearly black.
(<i>Z. carbonarius</i>, Bonaparte; <i>Z. sardus</i>, Suckow). In
some localities and islands only black specimens
occur.</p>

<p class='c032'>In the var. <i>caspius</i>, Iwan (<i>trabalis</i>, Pallas, <a href='#p05'>Plate V</a>.,
first figure; <i>persicus</i>, Jan, <a href='#p04'>Plate IV</a>., second figure),
from Hungary, Bosnia, Herzegovina, Corfu, Bulgaria,
<span class='pagenum'><a name='Page_173' id='Page_173'>173</a></span>
Roumania, Greece, Turkey, Southern Russia,
Northern Asia Minor, and North-West Persia, the
upper parts are pale olive or reddish-brown, with or
without brown or black spots, and each scale bears a
yellowish or pale brown longitudinal streak; there is
often a dark longitudinal streak on the nape; the
belly is uniform orange or red.</p>

<p class='c032'>Another variety, var. <i>asianus</i>, Boettger, from Asia
Minor, Rhodes, Cyprus, and Syria, has the upper
parts brown or olive, each scale with a longitudinal
light streak, and there are usually large black
spots relieved by yellowish shafts; the belly is red,
spotted or dotted with black. Melanism is frequent
in this form, such specimens being entirely black
except on the chin and throat, which are yellow
variegated with red.</p>

<p class='c032'>The very young of the typical form, as well
as that of the var. <i>viridiflavus</i>, has a striking livery
(<a href='#p04'>Plate IV</a>., first figure), the head and nape black
with yellow markings, or olive with black-edged yellow
markings, contrasting sharply with the pale olive-grey
of the body; the most conspicuous and constant of the
yellow markings consist of a bar between the eyes,
interrupted on the frontal shield, but sometimes continuous
with the yellow of the postoculars, five or six
small round spots on the parietal shields, and a
<b>V</b>- or <b>W</b>-shaped line just behind the parietals, followed
by one or two others separating the dark
cross-bars which may be present on the nape, and
<span class='pagenum'><a name='Page_174' id='Page_174'>174</a></span>
occasionally even continue some way down the
anterior part of the body. This livery persists in
some half-grown specimens.</p>

<p class='c032'>In young individuals from Syria (var. <i>asianus</i>) the
head is not differently coloured from the olive-brown
body, and the markings described above appear as
mere traces; on the other hand, the whole body has
black and yellow spots or cross-bars above, and the
belly is profusely marked with round black spots.</p>

<p class='c032'>In the new-born of the var. <i>caspius</i>, of which I
have examined only one specimen, 11 inches long,
from the Crimea, the head is olive-brown like the
body, which bears dark brown spots and narrow
cross-bars; and there is a dark brown streak along
the middle of the nape, as is sometimes the case in
the typical form. The belly is unspotted. A young
from Malta is intermediate in its markings between
the typical form and this variety.</p>

<p class='c032'>The young of the so-called black variety are not
black at birth, but similar to the normal young of the
races to which they belong.</p>

<p class='c032'>The four principal forms—<i>viridiflavus</i>, <i>gemonensis</i>,
<i>caspius</i>, and <i>asianus</i>—are so completely connected that
I cannot regard them as more than geographical
races or varieties.</p>

<p class='c032'><i>Size.</i>—This handsome snake grows to a length of
6 feet, the var. <i>caspius</i> even to 8 feet. I have seen a
specimen of this variety, from Salonica, which
measures
7<span class='nom'>2</span>⁄<span class='dem'>3</span>
feet.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_175' id='Page_175'>175</a></span>
<i>Distribution.</i>—From the Atlantic coast of Europe
to South-Western Asia. The typical form, in its
narrowest sense, inhabits the Southern Tyrol, the
north-eastern corner of Italy, and the countries to
the east of the Adriatic, as far as Greece and Crete.
The specimens from France, Switzerland, Italy,
Giglio, Montecristo, Elba, Corsica, Sardinia, Sicily,
and Malta, are mostly referable to the form known
as <i>Z. viridiflavus</i>. Farther to the east the species
is represented by the vars. <i>caspius</i> and <i>asianus</i>, of
which the distribution has been mentioned above.
From Spain, this snake is only on record from Catalonia,
not far from the French frontier.</p>

<p class='c032'>Rare or local in the north of its range (Maine-et-Loire,
Vienne, Indre, Sarthe, Haute-Saône, Yonne,
Aube, in France, Switzerland north of the Alps), it
is one of the commonest snakes in Italy and on the
borders and islands of the Adriatic, as well as on
practically all the islands of the Mediterranean east
of the Baleares. The highest altitudes at which it
has been met with are 3,900 feet in the Alps, 4,500
feet in the Balkan Peninsula.</p>

<p class='c032'><i>Habits.</i>—The name “Whip-snake,” under which
an American representative of this genus (<i>Z. flagelliformis</i>)
is known, like that of “Fouet” and “Loucinglant,”
which have been bestowed on it in some
parts of France, expresses the quick movements with
which, when captured, this snake lashes its long,
slender tail, at the same time furiously biting the
<span class='pagenum'><a name='Page_176' id='Page_176'>176</a></span>
hand that has seized it. The generic term <i>Zamenis</i>,
of Greek derivation, alludes to its viciousness, which
also accounts for its German name, “Zornnatter.”
This snake, occurring in Malta, may well have been
the “Viper” which fastened on the hand of St. Paul.
Some specimens have been kept for months in captivity
without losing their savage temper, hissing and
flying with open mouth at anyone approaching the
glass walls of their prison; others, on the other hand,
become quite tame in a very short time, such as one
which I kept for nearly two years. Except when
sunning itself on a cold early morning in the spring,
this snake is always on the alert, and difficult to
capture, uncoiling itself and darting away like an
arrow at the least disturbance. It lives in preference
among shrubs or on the edges of woods, avoiding
damp localities, and females at least appear to have
sedentary tastes. Lataste tells us of one, near
Bordeaux, which he repeatedly met for over two
years within 20 yards of the same spot, a bush
between a wood and a meadow, without ever being
able to capture it.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p05'><i>PLATE V</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_198a.jpg' width="400" height="107"
    alt=""/>
<p class='caption'>ZAMENIS GEMONENSIS, VAR. CASPIUS<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_198b.jpg' width="400" height="137"
    alt=""/>
<p class='caption'>ZAMENIS DAHLII<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_198c.jpg' width="400" height="125"
    alt=""/>
<p class='caption'>ZAMENIS HIPPOCREPIS<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'>The food of this snake is very varied, consisting of
voles and mice, young birds which it takes from the
nests, being a good climber on bushes and low trees,
occasionally of frogs, but above all of other reptiles:
lizards, slow-worms, and snakes, which it does not
attempt to crush before deglutition. It has even
been observed in Istria to eat locusts (<i>Acridium
ægyptium</i>) and sphyngid moths.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_177' id='Page_177'>177</a></span>
<i>Reproduction.</i>—Eggs, laid at the end of June or
beginning of July in a well-sheltered hole, are a little
over twice as long as broad, and measure 1·2 to
1·4 inches in length. The number of eggs is eight
to fifteen according to Fatio, about a dozen according
to Tomasini, five according to Werner. The
pairing was observed by Schreiber at the end of May,
the male and female seizing each other reciprocally
by the neck with their jaws; this mode of pairing
must not, however, be regarded as the rule in this
species, for in other cases observed by Schreiber and
by Honnorat the pairs were simply entwined by
their coils.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    7. <span class='sc'>Zamenis dahlii</span>, Fitzinger<br />
    Dahl’s Whip-Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Very slender; head narrow, snout moderately
prominent, obtuse. Tail about one-third of the
total length.</p>

<p class='c032'><i>Head-Shields.</i>—Rostral a little broader than deep,
just visible from above. Frontal not or but little
broader than the supraocular, once and two-thirds to
once and three-fourths as long as broad, as long as
or longer than its distance from the end of the snout,
shorter than the parietals. Loreal longer than deep.
One preocular, usually in contact with the frontal,
with a subocular below it; two postoculars. Temporals
2 + 2 or 2 + 3 (rarely 1 + 2). Upper labials
eight or nine, fourth and fifth or fifth and sixth
<span class='pagenum'><a name='Page_178' id='Page_178'>178</a></span>
entering the eye. Four or five lower labials in
contact with the anterior chin-shields, which are
shorter than the
posterior.</p>

<p class='c032'><i>Scales</i> with a
single apical pit,
very narrow, in
nineteen rows.
Ventral shields
very distinctly angulate
laterally,
205 to 218; anal
divided; subcaudals 98 to 132.</p>

<p><a id='f20' name='f20' href='#f20'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_201.jpg' width="200" height="150"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 20</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Coloration.</i>—Olive in front, with a few large black,
white- or yellow-edged spots on each side, the anterior
of which is sometimes confluent with its fellow and
forms a nuchal collar, as in the specimen figured on
<a href='#p05'>Plate V</a>.; the greater part of the body and tail
uniform pale olive, yellowish, or reddish above,
yellowish-white beneath. Head uniform olive-brown
above, the labial, preocular, and postocular shields
yellowish-white.</p>

<p class='c032'><i>Total Length.</i>—3 feet, rarely nearly 4 feet.</p>

<p class='c032'><i>Distribution.</i>—Southern Europe east of the Adriatic,
as far north as Dalmatia, Asia Minor, Cis- and Trans-Caucasia,
North-Western Persia, Cyprus, and Syria.
Has also been recorded from Lower Egypt.</p>

<p class='c032'><i>Habits.</i>—This snake is even more lively than
<i>Z. gemonensis</i>, and does not stand captivity long. It
<span class='pagenum'><a name='Page_179' id='Page_179'>179</a></span>
seeks dry, bushy localities, and feeds on small lizards,
occasionally on locusts. It does not seem to be very
common anywhere in Europe, except perhaps in
Dalmatia, whence most of the specimens sold by
dealers are imported.</p>

<p class='c032'><i>Reproduction.</i>—The pairing has been observed at
the end of May. According to Werner, the eggs
number usually three only, measuring
1<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches by <span class='nom'>1</span>⁄<span class='dem'>2</span>
inch.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    8. <span class='sc'>Zamenis hippocrepis</span>, Linnæus<br />
    The Horseshoe Whip-Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Slender; snout obtuse, feebly prominent.
Tail one-fifth to one-fourth of the total length.</p>

<p><a id='f21' name='f21' href='#f21'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_202.jpg' width="200" height="137"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 21</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral once and one-third to once
and a half as broad as deep, the portion visible
from above measuring
about
one-fourth to
one-third its
distance from
the frontal.
Frontal bell-shaped,
considerably
broader
in front than the
supraocular, once and one-fourth to once and a half
as long as broad, as long as or a little longer than its
distance from the end of the snout, shorter than the
<span class='pagenum'><a name='Page_180' id='Page_180'>180</a></span>
parietals. Loreal longer than deep, sometimes divided
into two. One preocular (sometimes divided into
two), in contact with the frontal; two postoculars; a
series of three or four suboculars, usually completely
separating the eye from the labials. Temporals
2 + 3 or 3 + 3. Eight or nine (rarely ten) upper
labials, fifth or sixth very rarely entering the eye.
Four lower labials in contact with the anterior chin-shields,
which are shorter than the posterior.</p>

<p class='c032'><i>Scales</i> with two apical pits, in twenty-five to
twenty-nine rows, usually twenty-seven. Ventral
shields very distinctly angulate laterally, 222 to 258;
anal divided (rarely entire); subcaudals 77 to 107.</p>

<p class='c032'><i>Coloration.</i>—Brown, pale olive, reddish, yellow, or
orange above, with a dorsal series of large dark brown,
black-edged rhomboidal spots, often bordered with
yellow, on each side of which is a series of smaller,
alternating spots (<a href='#p05'>Plate V</a>.); these spots may become
entirely black in the adult, and so large as to reduce
the ground colour to a mere network or series of
<b>X</b>-shaped pale lines. A dark cross-band between
the eyes, and a
<b>Λ</b>-
or horseshoe-shaped band on
the back of the head, which may be confluent with
an elongate spot on the nape; a light circle often
present in the middle between the parietal shields.
The spots often more or less confluent into three
longitudinal streaks on the tail. Yellow, orange, or
red beneath, with or without black dots, but constantly
with a lateral series of black spots, which
<span class='pagenum'><a name='Page_181' id='Page_181'>181</a></span>
may be very large or unite with the spots higher up
on the sides to form vertical bars.</p>

<p class='c032'><i>Size.</i>—Examples 5 feet long are on record; the
largest examined by me measures 4 feet 3 inches.</p>

<p class='c032'><i>Distribution.</i>—Spain and Portugal, Sardinia, Pantellaria,
Morocco, Algeria, Tunisia. Does not reach
the North of Spain nor penetrate into the Sahara.</p>

<p class='c032'><i>Habits.</i>—This very handsome snake is as a rule
as irascible as its European congeners. In Spain as
well as in Algeria it is often found about the dwellings
of man, occasionally entering houses in search of
mice, on which it principally feeds; it is also fond
of birds, and, climbing with great facility, plunders
the nests of sparrows in towns and villages. It
must be regarded as a useful commensal of man, and
deserving of protection.</p>

<p class='c032'><i>Reproduction.</i>—F. Doumergue found in a hole in a
rock near Oran, in September, the recently-laid eggs,
five in number and as large as pigeons’.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus COLUBER, Linnæus</span>
  </div>
</div>

<p class='c032'>Maxillary teeth equal or nearly equal in length.
Head elongate, distinct from neck; eye moderately
large, with round pupil. Body more or less elongate;
scales smooth or feebly keeled, with apical pits.
Tail moderate or long.</p>

<p class='c032'>This large genus, embracing close upon fifty
species, is represented in Europe, Asia, and North
and tropical America. Five species in Europe. Very
<span class='pagenum'><a name='Page_182' id='Page_182'>182</a></span>
nearly allied to <i>Zamenis</i>, but distinguished principally
by the posterior teeth of the upper jaw not being at
all enlarged, and, further, in being, like <i>Coronella</i>,
constrictors.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    9. <span class='sc'>Coluber quatuorlineatus</span>, Lacepède<br />
    (<i>Elaphis cervone</i>, Aldrovandi; <i>Coluber quatuorradiatus</i>,<br />
    Gmelin)<br />
    Aldrovandi’s Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Moderately slender. Snout obtuse,
scarcely prominent. Tail one-sixth to one-fourth
of the total
length.</p>

<p><a id='f22' name='f22' href='#f22'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_205.jpg' width="200" height="148"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 22</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral
broader
than deep, just
visible from
above. Frontal
once and one-fourth
to once
and a half as
long as broad, as long as its distance from the
rostral, shorter than the parietals. Loreal nearly
as long as deep, with one or two small shields
below it. One preocular, rarely divided, with
a subocular below it; two or three postoculars.
Temporals 2 + 3 or 3 + 4. Upper labials eight
(exceptionally nine), fourth and fifth (or fifth and
sixth) entering the eye. Four or five (rarely three)
<span class='pagenum'><a name='Page_183' id='Page_183'>183</a></span>
lower labials in contact with the anterior chin-shields,
which are longer than the posterior.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p06'><i>PLATE VI</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_206a.jpg' width="400" height="97"
    alt=""/>
<p class='caption'>COLUBER QUATUORLINEATUS<br />
<i>Young, after Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_206b.jpg' width="313" height="95"
    alt=""/>
<p class='caption'>COLUBER QUATUORLINEATUS<br />
<i>After Werner</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_206c.jpg' width="400" height="129"
    alt=""/>
<p class='caption'>COLUBER QUATUORLINEATUS, VAR. SAUROMATES<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_206d.jpg' width="400" height="120"
    alt=""/>
<p class='caption'>COLUBER DIONE<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'><i>Scales</i> feebly but distinctly keeled, except on the
outer rows, with two apical pits, in twenty-five (rarely
twenty-three or twenty-seven) rows. Ventral shields
not or but very obtusely angulate laterally, 195 to
234; anal divided; subcaudals 56 to 90.</p>

<p class='c032'><i>Coloration.</i>—Young (<a href='#p06'>Plate VI</a>., top) with three or
five alternating longitudinal series of dark brown,
black-edged spots on a yellowish, grey, or pale
brown ground, the spots of the median series largest,
transversely elliptical or rhomboidal; a dark streak
across the forehead, black bars on the labial shields,
and a black oblique streak from the eye to the angle
of the mouth. In specimens from Italy and the
countries bordering the Adriatic (the typical <i>C.
quatuorlineatus</i>) the markings very gradually disappear
with age, with the exception of the temporal streak,
whilst a pair of black streaks appear along each side
of the body, at a short distance from the head, the
lower corresponding to the postocular streak, the
adult being brown without spots, but four-lined
(<a href='#p06'>Plate VI</a>., second figure). In more eastern specimens
(<i>C. sauromates</i>, Pallas), which may be regarded as
representing the original form, the markings of the
young persist throughout life, or, if they disappear,
they are not replaced by dark streaks (<a href='#p06'>Plate VI</a>.,
third figure). Lower parts pale yellow, closely
spotted or marbled with brown, these markings
<span class='pagenum'><a name='Page_184' id='Page_184'>184</a></span>
usually disappearing in the adult, except on the tail.
Iris dark brown.</p>

<p class='c032'><i>Size.</i>—The largest European snake, stated to
reach a length of 8 feet. The largest specimen examined
by me measures, however, only
4<span class='nom'>1</span>⁄<span class='dem'>2</span>
feet.</p>

<p class='c032'><i>Distribution.</i>—Aldrovandi’s Snake inhabits Southern
Italy and Sicily, Istria, Croatia, Dalmatia, Herzegovina,
Greece, and eastwards to Southern Russia,
Transcaucasia, Asia Minor, and Persia. It has been
observed at an altitude of 2,600 feet in Herzegovina.</p>

<p class='c032'>All the specimens from Roumania, Bulgaria,
Turkey, and eastwards, belong to the var. <i>sauromates</i>,
which is regarded by some authors as worthy of
specific rank. The reported occurrence of <i>C. quatuorlineatus</i>
in various parts of France is certainly due to
confusion with <i>C. scalaris</i> and <i>C. longissimus</i>.</p>

<p class='c032'><i>Habits.</i>—Dry as well as marshy localities are the
abode of this large and handsome snake, which
often approaches the dwellings of man, attracted by
the poultry. Comparatively slow in its movements,
it is more easily captured than any of the other large
Colubrids of Europe, and does well in captivity,
where it should be provided with a tank, in which it
will remain for hours under water. It is as good at
swimming as at climbing. Biting readily when captured,
it becomes of gentle disposition after a short
period of captivity. In consequence of its slow, phlegmatic
temperament, it often allows itself to be picked
up when surprised in liberty, but as soon as it feels the
<span class='pagenum'><a name='Page_185' id='Page_185'>185</a></span>
grasp it turns round and defends itself. It appears
to feed exclusively on mammals and birds, up to the
size of a rat or dove, and will readily take dead food.
It has a predilection for eggs, and has often been
observed to swallow hens’ eggs.</p>

<p class='c032'><i>Reproduction.</i>—In Herzegovina pairing takes
place from the middle of June to the middle of July,
and the eggs are laid soon after, to hatch in September
or beginning of October. The eggs number six
to sixteen, and measure 2 inches by
1<span class='nom'>1</span>⁄<span class='dem'>3</span>
inches. The
young measure 8 to 14 inches at birth.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    10. <span class='sc'>Coluber dione</span>, Pallas<br />
    The Dione Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Similar to the preceding. Head more
convex, a little narrower; snout obtuse, scarcely
prominent. Tail about one-fifth of the total length.</p>

<p class='c032'><i>Head-Shields.</i>—Rostral broader than deep, just
visible from above. Frontal once and one-fourth
to once and a half as long as broad, as long as its
distance from the end of the snout, shorter than the
parietals. Loreal as long as deep, or a little longer
than deep. A large preocular, with a subocular
below it, the latter very exceptionally absent; two
or three postoculars. Temporals 2 + 3 or 3 + 3.
Upper labials eight or nine (very rarely seven),
fourth and fifth or fifth and sixth entering the eye.
Four or five lower labials in contact with the
<span class='pagenum'><a name='Page_186' id='Page_186'>186</a></span>
anterior chin-shields, which are nearly as long as
the posterior.</p>

<p class='c032'><i>Scales</i> smooth or faintly keeled, with two apical
pits, in twenty-five or twenty-seven (rarely twenty-three)
rows. Ventral
shields not or
but very obtusely
angulate laterally,
172 to 214; anal
divided; subcaudals
50 to 80.</p>

<p><a id='f23' name='f23' href='#f23'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_211.jpg' width="200" height="144"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 23</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Coloration.</i>—Pale
brown or
greyish-olive
above, with blackish cross-lines or dark brown or
reddish, black-edged spots, and usually two or three
more or less distinct pale longitudinal bands; two
dark longitudinal stripes on the nape, usually united
on the head and terminating on the frontal shield; a
curved dark cross-band from eye to eye, and another,
oblique, from the eye to the angle of the mouth.
Lower parts yellowish, usually dotted or spotted
with blackish.</p>

<p class='c032'><i>Size.</i>—Seldom exceeds a length of 3 feet. The
largest specimen examined by me measures 37
inches.</p>

<p class='c032'><i>Distribution.</i>—Across temperate Asia from Asia
Minor, Transcaucasia, and the southern border
of the Caspian Sea, to the Amur, Corea, and China.
<span class='pagenum'><a name='Page_187' id='Page_187'>187</a></span>
In Europe the habitat of this snake is restricted
to the steppes of Southern Russia, between the
Caucasus and the Lower Ural. The specimen
figured on <a href='#p06'>Plate VI</a>. is from Sarepta, on the Volga.</p>

<p class='c032'><i>Habits.</i>—This snake frequents arid, sandy localities,
and is only exceptionally found in small woods.
Nothing more is known of its habits.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    11. <span class='sc'>Coluber longissimus</span>, Laurenti<br />
    (<i>Coluber æsculapii</i>, Lacepède; <i>C. flavescens</i>, Gmelin)<br />
    The Æsculapian Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Slender. Snout obtuse, scarcely prominent;
head narrow. Tail about one-fifth to one-fourth
of the total length.</p>

<p><a id='f24' name='f24' href='#f24'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_212.jpg' width="200" height="130"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 24</span></p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral broader than deep, just
visible from above. Frontal once and one-fourth
to once and
one-third as
long as broad,
as long as its
distance from
the rostral or
the end of the
snout, shorter
than the parietals.
Loreal
as long as deep or longer than deep. One pre- and
two postoculars. Temporals 2 + 3. Upper labials
<span class='pagenum'><a name='Page_188' id='Page_188'>188</a></span>
eight or nine, fourth and fifth or fifth and sixth entering
the eye. Four or five lower labials in contact
with the anterior chin-shields, which are as long as
or a little longer than the posterior.</p>

<p class='c032'><i>Scales</i> smooth or feebly keeled on the posterior part
of the body, with two apical pits, in twenty-three
(rarely twenty-one) rows. Ventral shields distinctly
angulate laterally, 212 to 248; anal divided; subcaudals
60 to 91.</p>

<p class='c032'><i>Coloration.</i>—Yellowish-grey to dark olive-brown
above, some of the scales with whitish lines on the
margins occasionally forming a network; sometimes
with a yellowish vertebral stripe or with four darker
stripes along the body (var. <i>romanus</i>, Suckow); upper
lip, and often also a triangular patch on each side
behind the temple, pale yellow; a more or less distinct
dark band on the temple, and a vertical dark
bar below the eye (<a href='#p07'>Plate VII</a>., first figure). Lower
parts uniform pale yellow. Young (second figure)
with dark brown dorsal spots, forming four to seven
longitudinal series, a
<b>Λ</b>-shaped
black marking on the
nape behind the yellow nuchal blotches, which are
brighter than in the adult, a dark brown bar across
the forehead, and a black vertical line below the
eye; belly greyish or yellowish-olive. Iris dark grey
or brown. Tongue pinkish-brown.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p07'><i>PLATE VII</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_214a.jpg' width="400" height="85"
    alt=""/>
<p class='caption'>COLUBER LONGISSIMUS</p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_214b.jpg' width="348" height="68"
    alt=""/>
<p class='caption'>COLUBER LONGISSIMUS<br />
<i>Young, after Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_214c.jpg' width="400" height="96"
    alt=""/>
<p class='caption'>COLUBER LEOPARDINUS<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_214d.jpg' width="400" height="179"
    alt=""/>
<p class='caption'>C. LEOPARDINUS, VAR. QUADRILINEATUS<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'>Melanism is rare in this snake. Such specimens
are entirely black above and beneath (var. <i>niger</i>,
<span class='pagenum'><a name='Page_189' id='Page_189'>189</a></span>
Nikolsky), or blackish-grey to black above, dark
grey beneath (var. <i>subgriseus</i>, Werner), the angular
line on each side of the belly often remaining light.
An albino found near Vienna has been described as
pale orange-yellow above, with small white spots;
pupil and tongue red.</p>

<p class='c032'><i>Size.</i>—Grows to 6 feet. Specimens over
4<span class='nom'>1</span>⁄<span class='dem'>2</span>
feet
are, however, very rarely met with.</p>

<p class='c032'><i>Distribution.</i>—Generally distributed over the
greater part of Austria, Italy, with Sardinia and
Sicily, and the whole of South-Eastern Europe, this
snake has a very broken range in France, Switzerland,
Germany, and is found, quite isolated, as far
north as Denmark and Poland. According to
Segerus, quoted by Lacepède, it used to be quite
common near Copenhagen at the end of the
eighteenth century, but it is now much rarer. Its
northern limit in France is in Southern Brittany,
the Department Orne, and the Forest of Fontainebleau;
in Germany, Schlangenbad, near Wiesbaden,
perhaps also Baden-Baden and Treves. It is on
record from Southern Spain. Its discontinuous
distribution in Central Europe, and its presence
in various localities near former Roman thermal
stations, has been ascribed to its introduction from
Italy as an inmate of the temples erected to
Æsculapius; but I am more inclined to look upon
its sporadic occurrence in the North as the indication
of a once more widely distributed species
<span class='pagenum'><a name='Page_190' id='Page_190'>190</a></span>
now in process of extinction over part of its
range.</p>

<p class='c032'>In Asia the Æsculapian Snake is only found in
Transcaucasia. It occurs in the mountains as well
as in the plain, being recorded from 5,200 feet
altitude in the Tyrol, 3,200 feet in the Apennines.</p>

<p class='c032'><i>Habits.</i>—The Æsculapian Snake lives in woods;
among shrubby vegetation; in meadows, where it is
often found under haystacks; occasionally about
old walls. It climbs well, and often ascends trees.
Although a good swimmer, it seldom enters the
water of its own accord. It feeds chiefly on small
mammals, occasionally on birds and their eggs, and
lizards. Specimens which I kept in confinement fed
on mice only, refusing sparrows and lizards. Very
savage when fresh caught, most individuals soon
become tame, and like being handled by people to
whom they are accustomed, although still resenting
the intrusion of strangers. However, this snake
never becomes so thoroughly domesticated as the
Smooth Snake, and cannot be trained to take food
from the hand, according to R. Rollinat, who has
devoted many years to experiments on the taming
of reptiles. This observer had no difficulty in feeding
his Æsculapian Snakes on mice and voles placed
dead in their cage.</p>

<p class='c032'>This snake is particularly sensitive to cold, and
does not emerge until late in the spring from the
vole galleries and hollow trees which constitute its
<span class='pagenum'><a name='Page_191' id='Page_191'>191</a></span>
winter-quarters. It also avoids excessive heat, never
showing itself in the daytime during the hotter
months in the South of Europe.</p>

<p class='c032'><i>Reproduction.</i>—Pairing takes place between the
middle of May and the middle of June. The eggs
are laid towards the end of June or in July, in holes
in walls or hollow trees, under moss, sometimes even
in the dung-heaps of farms, and hatch in September.
According to trustworthy observers, the eggs, which
measure
1<span class='nom'>1</span>⁄<span class='dem'>2</span>
to 2 inches in length, and less than 1 inch
in width, number only five or six, rarely up to
eight.</p>

<p class='c032'>The young on emerging are highly suggestive of
young Grass-snakes in colour and markings, as well
as in their much less slender shape as compared with
the adult. They measure about 5 inches, and are
at once most ready to bite.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    12. <span class='sc'>Coluber leopardinus</span>, Bonaparte<br />
    (<i>Coluber quadrilineatus</i>, Pallas)<br />
    The Leopard Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Slender. Snout obtuse, scarcely prominent.
Tail about one-fifth of the total length.</p>

<p class='c032'><i>Head-Shields.</i>—Rostral broader than deep, just
visible from above. Frontal once and one-third to
once and a half as long as broad, as long as its distance
from the end of the snout, shorter than the parietals.
Loreal longer than deep. One pre- and two postoculars.
Temporals 1 + 2 or 2 + 3. Upper labials
<span class='pagenum'><a name='Page_192' id='Page_192'>192</a></span>
eight (rarely seven), fourth and fifth (rarely third and
fourth) entering the eye. Four or five lower labials in
contact with the anterior chin-shields, which are
longer than the
posterior.</p>

<p class='c032'><i>Scales</i> smooth,
with two apical
pits, in twenty-five
or twenty-seven
rows.
Ventral shields
rounded, not
angulate laterally,
222 to 260; anal divided; subcaudals 68-90.</p>

<p><a id='f25' name='f25' href='#f25'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_219.jpg' width="200" height="148"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 25</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Coloration.</i>—Typical form (<a href='#p07'>Plate VII</a>., third figure)
greyish or pale brown above, with one dorsal series
of dark brown, reddish-brown, or bright red, black-edged
transverse spots and a lateral alternating
series of smaller black spots with or without lighter
centres; usually a <b>[Y]</b>-shaped dark marking on the
occiput and nape; a crescentic black band from
eye to eye across the prefrontal shields, an oblique
black band from behind the eye to the angle of the
mouth, and a black spot or vertical bar below the
eye. Lower parts white, checkered with black, or
nearly entirely black. Iris reddish-golden.</p>

<p class='c032'>In some specimens (var. <i>quadrilineatus</i>) the dorsal
spots are replaced by two brown or red, black-edged
stripes bordering a pale greyish or yellowish vertebral
<span class='pagenum'><a name='Page_193' id='Page_193'>193</a></span>
stripe (<a href='#p07'>Plate VII</a>., fourth figure); such specimens
are so coloured from birth. This colour variety,
which is so strikingly different from the typical form,
is connected with the latter by the var. <i>schwoederi</i>,
Werner, in which the spots form two vertebral
series, and the var. <i>elsneri</i>, Werner, in which the light
vertebral band is broken up by dark transverse bars,
producing a ladder-like pattern.</p>

<p class='c032'><i>Size.</i>—Rarely exceeding a length of 3 feet.</p>

<p class='c032'><i>Distribution.</i>—Southern Italy, Sicily, Malta, Istria,
Dalmatia, and other parts of the Balkan Peninsula,
Grecian islands, Crimea, Asia Minor. The altitudinal
range does not extend beyond 1,600 feet.</p>

<p class='c032'><i>Habits.</i>—This is not only the prettiest European
snake as regards its markings, whether in the form
of spots or of stripes, but also the most graceful in its
movements. Unless compelled to fly for safety,
there is something slow and deliberate in its behaviour
which is more suggestive of <i>Coronella</i> than of
most other species of <i>Coluber</i>. It is fond of climbing,
and if the terrarium in which it is kept be provided
with a bush or small tree, it will spend most of the
time gracefully coiled round the branches. Usually
very savage when fresh caught, some specimens
become quite tame in captivity. In Dalmatia, where
it is not uncommon, this snake is found principally
among prickly shrubs, in hedges, or on old walls. It
awakens from its winter slumber later than other
South European snakes. Although occasionally
<span class='pagenum'><a name='Page_194' id='Page_194'>194</a></span>
taking lizards, its principal food consists of mammals
and birds, which are killed before being devoured,
the Leopard Snake being, like the other members of
the genus <i>Coluber</i>, a constrictor.</p>

<p class='c032'><i>Reproduction.</i>—According to Werner, the eggs, two
to five in number, are deposited in midsummer;
they are remarkably elongate:
2<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches long, <span class='nom'>2</span>⁄<span class='dem'>3</span>
inch
broad.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    13. <span class='sc'>Coluber scalaris</span>, Schinz<br />
    The Ladder Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Moderately slender. Snout pointed,
strongly projecting beyond the mouth. Tail one-sixth
to one-fifth of the total length.</p>

<p><a id='f26' name='f26' href='#f26'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_221.jpg' width="200" height="141"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 26</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral deeper than broad, forming
an acute angle above, wedged in between the internasals,
the portion visible from above nearly as long
as its distance
from the frontal.
Frontal
about once and
one-third to
once and a half
as long as broad,
as long as or
shorter than its
distance from
the end of the snout, nearly as long as the parietals.
Loreal longer than deep. One pre- and two or three
<span class='pagenum'><a name='Page_195' id='Page_195'>195</a></span>
post-oculars. Temporals 2 + 3 or 2 + 4. Upper
labials seven or eight (rarely nine), fourth or fourth
and fifth (or fifth and sixth) entering the eye. Four
or five lower labials in contact with the anterior chin-shields,
which may be either longer or shorter than
the posterior.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p08'><i>PLATE VIII</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_222.jpg' width="400" height="195"
    alt=""/>
<p class='caption'>COLUBER SCALARIS<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'><i>Scales</i> smooth, with two apical pits, in twenty-seven
(rarely twenty-five or twenty-nine) rows. Ventral
shields not angulate laterally, 201 to 220; anal
divided, rarely entire; subcaudals 48 to 68.</p>

<p class='c032'><i>Coloration.</i>—Young yellowish-grey, or pale brown,
above, with a series of regular <b>H</b>-shaped black or
blackish-brown markings along the back, forming a
ladder-like pattern—whence the name <i>scalaris</i>—and
small black spots on the sides; a <b>V</b>-shaped black
marking on the snout, a black oblique streak from
the eye to the angle of the mouth, and a black spot
below the eye; belly yellow, spotted or checkered
with black or nearly entirely black. These dorsal
markings disappear in the adult, and are replaced by
a pair of brown stripes running along the back
(<a href='#p08'>Plate VIII</a>.); the belly loses the black markings,
and becomes uniform yellow. Iris dark brown.</p>

<p class='c032'><i>Size.</i>—Grows to a length of
3<span class='nom'>1</span>⁄<span class='dem'>2</span>
feet, exceptionally
4<span class='nom'>1</span>⁄<span class='dem'>2</span>
feet.</p>

<p class='c032'><i>Distribution.</i>—The Mediterranean coast of France,
Spain and Portugal, and Minorca. Its occurrence in
Algeria is very doubtful.</p>

<p class='c032'><i>Habits.</i>—Not uncommon near the coast in France,
<span class='pagenum'><a name='Page_196' id='Page_196'>196</a></span>
in hedges and vineyards, often climbing on shrubs.
In the Spanish Peninsula, according to Boscá, it is
common in forests and on the sheltered side of
valleys, under stones or in holes in the ground. A
specimen I kept alive for a short time showed a more
furious temper than I have ever witnessed in any
snake, repeatedly flying with open mouth against the
glass of its cage whenever I entered the room in
which it was kept. Other specimens are reported to
have become quite tame after a certain time. It is
one of the quickest of European snakes, one of the
most difficult to catch; it is a good climber. The
food consists of mice, birds, and lizards; the young
are said to occasionally eat grasshoppers.</p>

<p class='c032'><i>Reproduction.</i>—According to J. von Fischer, the
eggs, nine in number, are deposited twenty-five days
after the pairing, which takes place in May or June,
and measure about 2 inches by
<span class='nom'>2</span>⁄<span class='dem'>3</span>
inch.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus CORONELLA, Laurenti</span>
  </div>
</div>

<p class='c032'>Maxillary teeth increasing in size posteriorly.
Head not or but slightly distinct from neck; eye
rather small, with round pupil. No subocular shields.
Body moderately elongate; scales smooth, with apical
pits. Tail moderate.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p09'><i>PLATE IX</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_226.jpg' width="400" height="211"
    alt=""/>
<p class='caption'>CORONELLA AUSTRIACA<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'>This genus, embracing about twenty species, is
represented in the different parts of the Northern
Hemisphere, extending a little beyond the Equator
in East Africa. Two species are European.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >

<span class='pagenum'><a name='Page_197' id='Page_197'>197</a></span>
14. <span class='sc'>Coronella austriaca</span>, Laurenti<br />
    (<i>Coluber lævis</i>, Lacepède)<br />
    The Smooth Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Moderately slender; snout more or less
prominent, sometimes decidedly pointed; tail one-fourth
(males) to one-sixth (females) of the total
length. The considerable differences to be observed
in the shape of the snout are merely individual, specimens
with more prominent snout and a corresponding
development of the
rostral shield (<i>C.
italica</i>, Fitz., <i>fitzingeri</i>,
Bonap.) occurring
over the
greater part of
the range of the
species.</p>

<p><a id='f27' name='f27' href='#f27'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_228.jpg' width="200" height="150"
    alt=""/>
<p class='caption'><span class='sc'>Fig.</span> 27 (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral
at least as
deep as broad, more or less produced posteriorly
between the internasals, the portion visible from
above at least half as long (in some specimens
quite as long) as its distance from the frontal,
rarely separating the internasals. Frontal once and
one-fourth to once and a half as long as broad,
much broader than the supraocular, as long as
or longer than its distance from the end of the
snout, shorter than the parietals, widely separated
<span class='pagenum'><a name='Page_198' id='Page_198'>198</a></span>
from the preocular. Nasal rarely undivided; loreal
longer than deep. One (very rarely two) pre- and two
postoculars. Temporals 2 + 2 or 2 + 3 (very rarely
1 + 2). Upper labials seven (rarely eight), third and
fourth (or fourth and fifth) entering the eye. Four
lower labials (rarely three) in contact with the anterior
chin-shields, which are as long as or longer than the
anterior.</p>

<p class='c032'><i>Scales</i> with one or two apical pits, the pit usually
single on the back and paired on the sides, in nineteen
(rarely twenty-one) rows.<a id='r2'/><a href='#f2' class='c038'><sup>[2]</sup></a> Ventral shields 153 to
199; anal divided (rarely entire); subcaudals 41 to 70.</p>

<p class='c032'><i>Coloration.</i>—Grey, brown, or reddish above, with
small blackish, dark brown, or brick-red spots usually
disposed in pairs, sometimes forming cross-bars;
sometimes with one or three lighter stripes; one or two
black dots precede on each scale the single or paired
apical pit; frequently two blackish, dark brown, or
brick-red stripes on the nape, usually confluent with
a large dark blotch on the occiput; the top of the
head occasionally nearly entirely blackish, especially
in the young; a dark streak on each side of the head,
from the nostril to the angle of the mouth, passing
through the eye, sometimes extending along the side
of the neck or even of the whole body. Lower
parts red, orange, brown, grey, or black, uniform or
speckled or closely spotted with black and white, the
sides often lighter (<a href='#p09'>Plate IX</a>.).</p>

<p class='c032'>
<span class='pagenum'><a name='Page_199' id='Page_199'>199</a></span>
A colour variety, of which I have examined a single
specimen from near Vienna, is pale brown above,
with four black lines along the anterior part of the
body, and two small, yellowish, dark-edged spots
close together on the back of the head, separated by
the suture between the parietal shields.</p>

<p class='c032'>Werner has described another variety, also from
near Vienna, which resembles <i>Coluber leopardinus</i>,
having two series of large, brown, dark-edged
spots along the back, some of the spots alternating,
others uniting across the back. Apparently very
similar to the last variety, and also said to be
suggestive of <i>Coluber leopardinus</i>, is the var. <i>scalaris</i>,
Sternfeld, from Lüneburg in Hanover, reddish-brown
above, with two rows of bright red, black-edged
spots, partly confluent and connected across
the spine by transverse bars producing a ladder-like
pattern. Specimens of a uniform greyish-brown,
without any markings, are very rare. The
var. <i>veithi</i>, Schreiber, established on a single specimen
from Carinthia, represents a case of melanism:
bluish-black, with the normal markings of an intense
black. Two specimens of a “black variety” are said
to have been found in this country, near Poole.</p>

<p class='c032'><i>Size.</i>—Seldom exceeds a length of 2 feet, and in
many districts, in England for instance, does not
appear to often reach that size. The largest specimen,
from Austria, examined by me, measures
25 inches; one from Hampshire measures 24 inches.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_200' id='Page_200'>200</a></span>
<i>Distribution.</i>—The range of the Smooth Snake
extends over nearly the whole of Europe, as far
north as 63° in Norway; it becomes rare and more
local in the south, being absent from part of Spain
and the islands of the Mediterranean, with the
exception of Sardinia. It is common in the hilly
parts of Belgium, Northern and Central France,
Germany, and Austria. In Sweden it appears to be
restricted to the oak region. In Great Britain it
has been found in four counties in the South of
England: Surrey, Hampshire, Dorsetshire, and Berkshire,
in some parts of which it is less uncommon
than usually supposed. Its reported occurrence in
Dumfriesshire is the result of an error; the snake
figured as <i>Coluber dumfriesiensis</i> represents an American
species. In a very interesting article written for
<i>Science Gossip</i> in 1888, Mr. A. L. Beldy says that
about 1868, when Bournemouth was but a very
small village, surrounded by large expanses of moorland,
<i>Coronella austriaca</i> was extraordinarily abundant,
and during a hot summer examples were to be seen
literally in scores and great numbers were killed.
Since then, however, their numbers have gradually
decreased. About 1880 the snake was occasionally
found near Wellington College, Berks, and as many
as five were captured by one person in the course of
one year; it is believed to be now extinct in that
neighbourhood. From South-Eastern Europe the
range of this species extends to South-Western Asia.
<span class='pagenum'><a name='Page_201' id='Page_201'>201</a></span>
The ascertained altitudinal range is 4,000 feet in
the Alps, 6,000 feet in Bosnia, and 6,500 feet in the
Caucasus.</p>

<p class='c032'><i>Habits.</i>—The Smooth Snake lives on heathland,
stony wastes, and wooded hills, showing a preference
for dry localities. Although not infrequent on the
Dorsetshire and Hampshire heaths, where it was first
discovered in 1853, it was not recorded as a British
reptile until 1859; it was discovered much later on
the sandy heaths between Haslemere and Farnham,
where it occurs in small numbers, and in Berkshire.
These localities are likewise inhabited by the rarer
British lizard, the Sand Lizard. Notwithstanding
its gentle, timid appearance, this snake when fresh
caught is usually very ready to bite; either it snaps
angrily, or, without hissing or other warning, it
suddenly fastens its jaws into the finger of its
captor, even if it be gently handled. The food
consists mostly of lizards, occasionally of slow-worms
or small snakes, more rarely of voles or
mice, even shrews, which are seized, constrictor-like,
and crushed by the coils of the body. O. von
Tomasini has observed one swallowing a <i>Coluber
longissimus</i> as large as itself.</p>

<p class='c032'>In Central Europe this snake becomes active
towards the end of March or beginning of April, and
retires in September or October. It does well in
captivity, and becomes very tame. It is one of the
most intelligent of snakes, second to none in educability;
<span class='pagenum'><a name='Page_202' id='Page_202'>202</a></span>
it can be trained to feed in the hand of
its master.</p>

<p class='c032'><i>Reproduction.</i>—The Smooth Snake pairs in early
spring, and is ovoviviparous. The young, two to
fifteen in number, are born late in August or in
September, enveloped by a thin membrane which
they tear immediately; they measure 5 to 6 inches.
Embryos
3<span class='nom'>1</span>⁄<span class='dem'>2</span>
or 4 inches long have the scaling and
the characteristic markings fully developed, but the
scales and shields much abbreviated, the former
broader than long. A dicephalous young is preserved
in the Bosnian Museum at Sarajev, and another
was caught near Karlsruhe, in Germany, in 1881,
and kept alive for some time. According to Rollinat,
a second autumnal pairing sometimes takes place in
France.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    15. <span class='sc'>Coronella girondica</span>, Daudin<br />
    (<i>Coluber riccioli</i>, Metaxa)<br />
    The Southern Smooth Snake
  </div>
</div>

<p class='c032'>Distinguished from the preceding by a somewhat
more slender form, a more obtuse, scarcely prominent
snout, a much lower rostral shield, which is considerably
broader than deep and just visible from
above, not penetrating between the internasals, constantly
eight upper labials, fourth and fifth entering
the eye, and the scales in twenty-one (rarely nineteen
or twenty-three) rows. Ventrals 170 to 200;
anal divided; subcaudals 49 to 72.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >

<span class='pagenum'><a name='Page_203' id='Page_203'>203</a></span>
<a id='p10'><i>PLATE X</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_234a.jpg' width="192" height="32"
    alt=""/>
<p class='caption'>CONTIA MODESTA<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_234b.jpg' width="500" height="186"
    alt=""/>
<p class='caption'>CORONELLA GIRONDICA<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'><i>Coloration.</i>—Brown, greyish, yellowish, or reddish
above, with dark brown or black spots or transverse
bars, sometimes with four dark stripes in addition;
dark dots in front of the apical pits as in the preceding
species; a pair of elongate dark spots or a <b>U</b>-shaped
marking on the nape; a dark streak from the eye
to the angle of the mouth, and a dark cross-bar
from eye to eye, across the prefrontal shields; a dark
line below the eye.
Lower parts yellow,
orange, or coral red,
with large, mostly
quadrangular black
spots, often arranged
in chess-board
fashion, or
with two series of
black spots (<a href='#p10'>Plate X</a>.), which may be confluent into two longitudinal
bands.</p>

<p><a id='f28' name='f28' href='#f28'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_236.jpg' width="200" height="154"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 28</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Total Length.</i>—26 inches.</p>

<p class='c032'><i>Distribution.</i>—South of France (as far north as
the Charente-Inférieure to the west, the Dauphiné
to the east), the whole of Spain and Portugal,
Southern Tyrol, Italy, and Sicily. It has not been
recorded from higher than 2,500 feet in the
Alps. Rare in Northern Morocco and Algeria. In
many localities in Europe it occurs alongside with
<i>C. austriaca</i>.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_204' id='Page_204'>204</a></span>
<i>Habits.</i>—All that is known to me of the habits
of this close ally of the preceding species is derived
from the works of Bonaparte, Gené, and Schreiber,
and from a note by Gachet, who observed it near
Bordeaux and described it under the name of
<i>Coluber rubens</i>. According to these authors, it
frequents dry and rocky localities as well as old
walls, in which it finds a refuge and a good supply
of the lizards on which it feeds. A large specimen
from Albano, near Rome, preserved in the Genoa
Museum, had swallowed a full-grown <i>Chalcides
tridactylus</i>. This <i>Coronella</i> is crepuscular, rarely
showing itself in the daytime, leaving its retreat
only after sunset, and has been observed to crawl
about by moonlight. Its movements are slow,
which accounts for crushed specimens being often
met with on paths or roads. Contrary to the rule
in <i>C. austriaca</i>, it is extremely gentle, seldom attempting
to bite.</p>

<p class='c032'><i>Reproduction.</i>—Whether this species is ovoviviparous,
like its European congener, has not, I think,
been ascertained. All we know on this matter is
that a female found dead on a road near Bordeaux
by M. Lataste at the end of June contained eggs
which showed no trace of embryos. This does not,
however, settle the question, as the young would
not be born until at least two months later. According
to Gené, pairing takes place in May, when
specimens have been observed to congregate in
considerable numbers.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >

<span class='pagenum'><a name='Page_205' id='Page_205'>205</a></span>
<span class='sc'>Genus</span> CONTIA, <span class='sc'>Baird and Girard</span>
  </div>
</div>

<p class='c032'>Maxillary teeth subequal. Head not or but
slightly distinct from neck; eye moderate or rather
small, with round pupil. Nasal single; no subocular
shields. Body moderately elongate; scales smooth,
with apical pits. Tail moderate.</p>

<p class='c032'>This genus, with certain modifications in the
above definition, is made to embrace about twenty-five
species from South-Western Asia and Sind and
North and Central America. One of the species
inhabiting Asia extends into a very small part of
Europe.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    16. <span class='sc'>Contia modesta</span>, Martin<br />
    The Dwarf Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Moderately slender. Head small, quite
flat above; snout obtuse, feebly prominent. Length
of tail four to five times in the total length.</p>

<p class='c032'><i>Head-Shields.</i>—Rostral a little broader than deep,
visible from above. Suture between the internasals
as long as or a little shorter than that between the
prefrontals. Frontal once and a half to once and
two-thirds as long as broad, as long as or longer
than its distance from the end of the snout, shorter
than the parietals, as broad as or a little broader
than the supraocular, widely separated from the
preocular. Nostril in the middle or upper part of
the nasal. Loreal square or longer than deep. One
<span class='pagenum'><a name='Page_206' id='Page_206'>206</a></span>
(rarely two) pre- and two (rarely one) postoculars.
Temporals 1 + 2; parietal sometimes nearly touching
the fifth upper labial. Upper labials seven,
third and fourth entering the eye. Four (rarely
five) lower labials in
contact with the anterior
chin-shield;
posterior chin-shields
smaller than the anterior,
and separated
from each other by
one or two rows of
scales.</p>

<p><a id='f29' name='f29' href='#f29'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_239.jpg' width="200" height="161"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 29</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Scales</i> with a single
apical pit, in seventeen rows. Ventral shields 150
to 191; anal divided; subcaudals 53 to 78.</p>

<p class='c032'><i>Coloration.</i>—Not unlike that of a young <i>Zamenis
gemonensis</i>. Greyish-olive above, uniform or each
scale lighter in the centre. The greater part of the
upper surface of the head behind the snout, together
with the nape, black in the young, with a
yellow cross-bar or a pair of yellow spots between
the eyes, the bar sometimes confluent with the
yellow postoculars, and a horseshoe-shaped band
of the same colour on the temples and across the
occiput (<a href='#p10'>Plate X</a>.); the black of the nape again edged
with yellow behind. More or less distinct traces
of these markings are preserved in adult specimens.
Upper lip yellowish, with black spots or bars on
<span class='pagenum'><a name='Page_207' id='Page_207'>207</a></span>
the sutures between the shields. Lower parts uniform
white or yellowish.</p>

<p class='c032'>In the var. <i>semimaculata</i>, Boettger, from Chios,
small dark spots are scattered over the upper parts
of the anterior half of the body.</p>

<p class='c032'><i>Size.</i>—This snake rarely reaches a length of
19 inches. It is the smallest Colubrid of Europe.</p>

<p class='c032'><i>Distribution.</i>—The Caucasus up to about 5,000
feet, Asia Minor, Chios, Cyprus, Syria, Mesopotamia,
and North-Western Persia. The northern slope
of the Caucasus appears to be the only part of
Europe included in its habitat. The British Museum
possesses two specimens labelled as from Constantinople,
but the presence of this species in European
Turkey requires confirmation.</p>

<p class='c032'>A closely allied species, which has been confounded
with <i>C. modesta</i>, <i>C. collaris</i> (Ménétriès), and which
also inhabits the Caucasus without having been
recorded from the northern slope, is distinguished
by having the scales in fifteen rows (very rarely
seventeen), and the posterior chin-shields in contact
with each other.</p>

<p class='c032'><i>Habits.</i>—Nothing is known as regards this species,
but the North American members of the genus
<i>Contia</i> are chiefly insectivorous and oviparous.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus</span> CŒLOPELTIS, <span class='sc'>Wagler</span>
  </div>
</div>

<p class='c032'>Maxillary teeth small and subequal, followed after
a short interspace by one or two very large grooved
<span class='pagenum'><a name='Page_208' id='Page_208'>208</a></span>
fangs situated below the posterior border of the eye;
anterior mandibular teeth strongly enlarged. Head
not very distinct from neck, with angular canthus
rostralis and projecting supraocular; eye large, with
round pupil; nostril a crescentic slit in a single or
divided nasal. Body elongate; scales smooth, more
or less distinctly grooved longitudinally in the adult,
with apical pits. Tail moderately long.</p>

<p class='c032'>The range of this genus, which comprises only
two species, extends over Southern Europe, South-Western
Asia, and North Africa.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    17. <span class='sc'>Cœlopeltis monspessulana</span>, Hermann<br />
    (<i>Natrix lacertina</i>, Wagler; <i>Coluber insignitus</i>, I. Geoffroy)<br />
    The Montpellier Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Slender; head elongate, narrow, concave
above on the snout and between the eyes; snout
projecting, rounded, with raised canthus and concave
loreal region. Tail about one-fifth to one-fourth
of the total length.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p11'><i>PLATE XI</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_242a.jpg' width="400" height="155"
    alt=""/>
<p class='caption'>CŒLOPELTIS MONSPESSULANA<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_242b.jpg' width="343" height="80"
    alt=""/>
<p class='caption'>MACROPROTODON CUCULLATUS</p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_242c.jpg' width="185" height="113"
    alt=""/>
<p class='caption'>TARBOPHIS IBERUS<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_242d.jpg' width="400" height="87"
    alt=""/>
<p class='caption'>TARBOPHIS FALLAX</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral nearly as deep as broad,
just visible from above. Internasals much shorter
than the prefrontals. Frontal very narrow, twice to
twice and a half as long as broad, its width in the
middle not more than half that of the supraocular,
widening in front and extending beyond the supraoculars
to join the preoculars, longer than its distance
from the end of snout, as long as or a little longer
<span class='pagenum'><a name='Page_209' id='Page_209'>209</a></span>
than the parietals. Two loreals. One preocular, the
upper portion of which is much enlarged, and encroaches
upon the area occupied in other snakes by
the prefrontal and the supraocular; two (rarely three)
postoculars. Temporals 2 + 3 or 4. Upper labials
eight (rarely nine), fourth and fifth (or fifth and
sixth) entering the eye. Four or five lower labials
in contact with the anterior chin-shields, which are
as long as or shorter than the posterior.</p>

<p class='c032'><i>Scales</i> with
single apical
pits, in seventeen
or nineteen
rows,
longitudinally
grooved in the
adult, less distinctly
in the
young. Ventral
shields 160 to 189; anal divided; subcaudals 68
to 102.</p>

<p><a id='f30' name='f30' href='#f30'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_244.jpg' width="200" height="126"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 30</span></p>
</div>

<p class='c032'><i>Coloration.</i>—The young is elegantly marked with
dark brown and yellowish-white on a pale brown
ground. On the head, the principal dark markings
usually are an oblique band on the posterior half of the
supraocular shield, and another, or a large spot, on
the parietal, sometimes produced backwards, and
forming with its fellow a
<b>Λ</b>-shaped
band, separated
from a large occipital blotch by a yellowish space;
<span class='pagenum'><a name='Page_210' id='Page_210'>210</a></span>
anterior half of the frontal shield and shields on the
snout edged with dark brown; a dark streak, sometimes
broken up into small spots, on the temporal
region; yellow spots on the pre- and post-oculars;
lips brown, with large, yellow, black-edged spots, or
yellow with brown spots; chin with three brown
longitudinal streaks. Back with a vertebral series of
large roundish dark spots or narrow cross-bars;
small spots on the sides, these sometimes forming
longitudinal series or accompanied by yellowish streaks
or dots; these markings often confluent into three
longitudinal streaks on the tail. Belly pale brownish,
greyish, or reddish, with numerous pale spots, sometimes
with a dark brown line on each side. The
adult is greyish, reddish-brown, or olive above. Some
specimens preserve more or less the markings of the
young, and the dark dorsal markings (<a href='#p11'>Plate XI</a>.) may
be edged with yellowish and ocellar in appearance
(var. <i>insignitus</i>, Geoffroy); the belly is yellowish, with
small dark spots which usually form longitudinal
series, and may be confluent into streaks. A variety
common in Dalmatia (<i>neumayeri</i>, Fitzinger) is brown
or olive above, without spots, sides with a bluish-grey
lateral band, the scales on which are edged with
black, the belly uniform yellow. Other specimens
are brown or reddish, with light edges to the scales
on the sides, or with yellowish lateral lines, or dark
olive or dark brown above and black on the sides,
each scale with a yellowish central spot; in the last-mentioned
<span class='pagenum'><a name='Page_211' id='Page_211'>211</a></span>
the second third of the back may be almost
entirely black, and the belly dark olive-grey in the
middle and yellowish on the sides. Iris brown,
with a golden or coppery circle round the pupil.</p>

<p class='c032'><i>Size.</i>—This handsome snake grows to a length of
6<span class='nom'>1</span>⁄<span class='dem'>2</span>
feet. Specimens 5 to 6 feet long are not uncommon.</p>

<p class='c032'><i>Distribution.</i>—Mediterranean coast of France and
Western Liguria, Spain and Portugal, Sicily, Lampedusa,
eastern coast of the Adriatic, Greece and
eastern islands of the Mediterranean, Mediterranean
coast of Asia and Sinaitic Peninsula, eastwards to
the Caucasus and Persia, North Africa from Egypt
to Rio de Oro. It is not known to occur above
2,300 feet altitude in Europe.</p>

<p class='c032'><i>Habits.</i>—A lively, swift snake, living on land and
on low bushes, often found near human habitations.
Some specimens are very vicious, whilst others show
a gentle disposition after a short period of captivity.
A specimen nearly 6 feet long, which I kept for
some time, never attempted to bite when handled,
and some have become so tame as to take food from
the hand. The sense of sight appears to be better
developed than in any other European snake. The
food consists chiefly of mammals, even large rats
and young rabbits, birds such as chickens, partridges,
and quails, lizards, and other snakes, which, if of
considerable size, are not swallowed until paralyzed
or killed by the effect of the poison. In Eastern
<span class='pagenum'><a name='Page_212' id='Page_212'>212</a></span>
Europe, <i>Vipera ammodytes</i> is said to be the principal
enemy of <i>Cœlopeltis</i>, and the two snakes are consequently
seldom found together in the same locality.</p>

<p class='c032'>Many experiments have been made on the action
of the poison of this Opisthoglyph. Peracca and
Deregibus, as well as, later, Phisalix, found a striking
similarity with the symptoms of Cobra poison in
their experiments on small animals, the suspension
of the respiration occurring in a few minutes, the
blood being otherwise unaffected. It has been
stated by some authors that <i>Cœlopeltis</i> poison has
little or no action on man, but a French zoologist,
E. Taton-Baulmont, having been bitten in the index-finger
by a four-foot-long specimen at Algiers, the
swelling extended within thirty hours up to the
shoulder, and was accompanied by fever and nervous
troubles. As a rule, however, the bite of this snake
has no poisonous effect on man, from the fact that
the fangs conveying the venom are situated so far
back in the mouth as not to come into action.</p>

<p class='c032'><i>Reproduction.</i>—According to Werner, the eggs,
four to twelve in number, are laid in July, and
measure 2 inches in length and
<span class='nom'>1</span>⁄<span class='dem'>2</span>
inch in width.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus MACROPROTODON, Guichenot</span>
  </div>
</div>

<p class='c032'>Maxillary teeth few and very unequal in size, fourth
and fifth or fifth and sixth enlarged and followed by
an interspace, the two last teeth fang-like and grooved,
situated just behind the eye; sixth mandibular tooth
<span class='pagenum'><a name='Page_213' id='Page_213'>213</a></span>
fang-like, and separated from the remainder by an
interspace. Head slightly distinct from neck; eye
rather small, the pupil vertically elliptic or subelliptic
when contracted. Body moderately elongate;
scales smooth, with apical pits. Tail moderate
or rather short.</p>

<p class='c032'>A single species.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    18. <span class='sc'>Macroprotodon cucullatus</span>, I. Geoffroy<br />
    The False Smooth Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Very similar to the Smooth Snakes, with
which it has been confounded, but snout broader and
very strongly depressed.
Tail
five and a half to
six and a half
times in the total
length.</p>

<p><a id='f31' name='f31' href='#f31'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_248.jpg' width="200" height="141"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 31</span></p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral
at
least twice as
broad as deep,
not or but scarcely visible from above. Internasals
as long as or a little shorter than the prefrontals.
Frontal not much broader than the supraocular
in the adult, once and a half to twice as
long as broad, as long as or longer than its distance
from the end of the snout, shorter than the
parietals. Nasal usually semidivided. Loreal once
<span class='pagenum'><a name='Page_214' id='Page_214'>214</a></span>
and a half to twice as long as deep. One preocular,
extending to the upper surface of the head, but not
reaching the frontal; two (rarely one or three) postoculars.
Temporals 1 + 2. Upper labials eight, fourth
and fifth entering the eye, sixth usually in contact
with the parietal. Four or five lower labials in contact
with the anterior chin-shields, which are as long
as or a little shorter than the posterior.</p>

<p class='c032'><i>Scales</i> with mostly single apical pits, the pits
sometimes paired on the sides of the body, in twenty-one
or twenty-three rows (nineteen to twenty-five in
North African specimens). Ventral shields 153 to
192; anal divided; subcaudals 40 to 54.</p>

<p class='c032'><i>Coloration.</i>—Pale brown or greyish above, with
small dark brown or blackish spots or with more or
less distinct darker and lighter longitudinal streaks.
Upper surface of head with dark brown vermiculations;
a dark brown or black, often light-edged
occipito-nuchal band, extending downwards to the
gular region and produced forwards into a point to
between the parietal shields; a dark brown or black
streak on each side of the head from the end of the
snout, through the eye, to the last lower labial shield,
traversing the four last upper labials, which are yellowish
above and below the streak (<a href='#p11'>Plate XI</a>.). Lower
parts yellow or coral red, with black spots, which
may form a tessellated pattern, two longitudinal
series, or be so crowded as to fuse into a band along
the middle of the belly and tail.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_215' id='Page_215'>215</a></span>
The above description is taken from Spanish
specimens (Badajos, Algeciras, Andalucia), but the
variations are very great when we take North Africa
into consideration. The nuchal band may be
narrow or broken up into spots, the median of
which sometimes forms a longitudinal streak, or
so much enlarged as to fuse with the dark markings
on the upper surface of the head; in some specimens
(from Morocco and Algeria) the upper surface of the
head and the nape may be entirely ink black, or the
whole head black above and beneath with the exception
of a whitish streak bordering the upper lip.
The dark streak from the eye to the angle of the
mouth may be absent, or reduced to a short oblique
streak below the eye. Irrespective of the variations
in the markings of the upper parts, the lower parts
may be more or less spotted with black, or immaculate.</p>

<p class='c032'>Some specimens of this small snake bear a general
resemblance to <i>Coronella girondica</i>, with which <i>Macroprotodon</i>
has sometimes been confounded. But a
careful examination of its whole structure shows it
to be more affine to <i>Cœlopeltis</i> and <i>Tarbophis</i>, the
other European representatives of the Opisthoglyphous
Colubrids.</p>

<p class='c032'><i>Size.</i>—The largest European specimen examined
measures
17<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches. Specimens up to 22 inches
long occur in Algeria and Tunisia.</p>

<p class='c032'><i>Distribution.</i>—In Europe this snake is only known
<span class='pagenum'><a name='Page_216' id='Page_216'>216</a></span>
from Spain (Estremadura, New Castille, Andalucia),
Portugal (Alemtejo), the Balearic Islands (Majorca
and Minorca), and the island of Lampedusa. In
North Africa it is generally distributed from the
north coast of Egypt to the Rio de Oro; in Algeria
it penetrates into the northern parts of the Sahara.
The specimen figured on <a href='#p11'>Plate XI</a>. is from Algeciras.</p>

<p class='c032'><i>Habits.</i>—Appear to be similar to those of <i>Coronella
girondica</i>. Crepuscular in its habits, it is usually
found under stones or in burrows in the ground.
Unless pursued, when it darts off with great rapidity,
its movements are slow. It is very ready to bite,
but no experiments have been made on the effects
of its poison. The food consists chiefly of small
lizards.</p>

<p class='c032'><i>Reproduction.</i>—All that is known on this head is
that, according to Doumergue, eggs are laid in July in
Algeria.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus TARBOPHIS, Fleischmann</span>
  </div>
</div>

<p class='c032'>Maxillary teeth few, anterior longest, gradually
decreasing in size posteriorly, and followed, after an
interspace, by a pair of enlarged, grooved fangs,
situated below the posterior border of the eye;
anterior mandibular teeth strongly enlarged. Head
distinct from neck; eye moderate or rather small,
with vertically elliptic pupil. Body moderately
elongate; scales smooth, oblique, with apical pits.
Tail moderate or rather short.</p>

<p class='c032'>The eight species of this genus inhabit South-Eastern
<span class='pagenum'><a name='Page_217' id='Page_217'>217</a></span>
Europe, South-Western Asia, and Africa.
Two are dealt with here.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    19. <span class='sc'>Tarbophis fallax</span>, Fleischmann<br />
    (<i>Ailurophis vivax</i>, Bonaparte)<br />
    The Cat-Snake
  </div>
</div>

<p class='c032'><i>Form.</i>—Moderately slender. Head much depressed.
Tail five and a half to seven times in the
total length.</p>

<p><a id='f32' name='f32' href='#f32'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_252.jpg' width="200" height="135"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 32</span></p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral broader than deep, just
visible from above. Internasals shorter than the prefrontals.
Frontal
much
broader than
the supraocular,
once and
one-fourth to
once and a
half as long as
broad, as long
as its distance
from the end of the snout, shorter than the
parietals. Nasal divided or semidivided. Loreal
twice and a half to thrice as long as deep, entering
the eye below the preocular, which is in contact with
the frontal. Two (rarely three) postoculars. Temporals
small, scale-like, 2 or 3 + 3 or 4. Upper
labials eight (rarely seven or nine), third, fourth, and
fifth (rarely fourth and fifth, or fourth, fifth, and
<span class='pagenum'><a name='Page_218' id='Page_218'>218</a></span>
sixth) entering the eye. Three or four lower labials
in contact with the anterior chin-shields; posterior
chin-shields very small and widely separated from
each other by scales.</p>

<p class='c032'><i>Scales</i> with single or paired apical pits, in nineteen
or twenty-one rows, usually nineteen in European
specimens. Ventral shields 186 to 222; anal divided;
subcaudals 48 to 73.</p>

<p class='c032'><i>Coloration.</i>—Greyish above, with 40 to 57 brown
or black spots or bars on the body; a lateral series
of smaller spots or vertical bars, alternating with the
dorsals; the first spot, on the nape, elongate, usually
with one or three linear processes in front, extending
on the head (<a href='#p11'>Plate XI</a>.); usually a dark streak on each
side of the head, from the eye to the angle of the
mouth. Lower parts whitish, speckled, spotted, or
marbled with grey or brown. Iris brown, with a
golden circle round the pupil.</p>

<p class='c032'><i>Size.</i>—This species grows to a length of 2 feet
10 inches.</p>

<p class='c032'><i>Distribution.</i>—From Istria and Dalmatia to Greece,
the Archipelago, Constantinople, Asia Minor, Cyprus,
and Northern Syria; 2,600 feet appears to be its
altitudinal limit.</p>

<p class='c032'><i>Habits.</i>—Although to a certain extent crepuscular
or nocturnal, the Cat-snake is often seen hunting in
the daytime, its food consisting almost exclusively
of lizards, rarely of small mammals. Its movements
are rather slow. The names Katzenschlange and
<span class='pagenum'><a name='Page_219' id='Page_219'>219</a></span>
<i>Ailurophis</i>, translated Cat-snake, probably originated
from the way in which this snake stalks its prey, and
suddenly pounces upon it. According to Eiffe, the
poison causes the death of a <i>Lacerta vivipara</i> in one
minute, and P. de Grijs observed the larger <i>Lacerta
agilis</i> to die in two or three minutes. As a rule
even fresh-caught specimens allow themselves to be
handled without attempting to bite; some specimens,
on the other hand, are very savage. Stony localities,
old walls, and ruins, are the favourite abodes of this
snake, which does well in captivity.</p>

<p class='c032'><i>Reproduction.</i>—Seven or eight eggs are laid in
July; they measure about
1<span class='nom'>1</span>⁄<span class='dem'>4</span>
inches in length and
<span class='nom'>1</span>⁄<span class='dem'>2</span>
inch in width.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    20. <span class='sc'>Tarbophis iberus</span>, Eichwald<br />
    The Caucasian Cat-Snake
  </div>
</div>

<p class='c032'>Very closely allied to the preceding, and differing
from it only in the following points: Parietals
shorter, slightly longer than the frontal, and anal
entire. Loreal twice to twice and a half as long as
deep. Fourth and fifth, or third, fourth, and fifth,
labials entering the eye. Scales in nineteen or
twenty-one rows. Ventrals 203 to 235; subcaudals
54 to 70.</p>

<p class='c032'>Grey above, with 35 to 40 blackish spots on the
body, the anterior largest and darkest; a lateral
series of smaller spots or vertical bars. Lower parts
<span class='pagenum'><a name='Page_220' id='Page_220'>220</a></span>
blackish, with small whitish spots and dots. Reaches
a length of
3<span class='nom'>1</span>⁄<span class='dem'>2</span>
feet.</p>

<p class='c032'>This species inhabits the Caucasus, and, being on
record from the northern slope (Kuban River), has
to be included in the European fauna. It occurs
also in Mesopotamia, a specimen from Bagdad being
preserved in the British Museum. The young
specimen figured on <a href='#p11'>Plate XI</a>. is stated to be from
Constantinople.</p>

<p class='c032'>Nothing is known of its habits, which are probably
the same as those of <i>Tarbophis fallax</i>.</p>

<div class='chapter'>
  <h2 id='fa04' class='c014'><span class='sc'>Fourth Family: VIPERIDÆ</span></h2>
</div>

<p class='c041'>Maxillary, palatine, and pterygoid bones movable,
the first much abbreviated, erectile perpendicularly
to the large transverse bone, and supporting a pair
of large canaliculated poison fangs; mandible without
coronoid bone. No vestiges of pelvic arch.</p>

<p class='c032'>All more or less poisonous, some being among the
most dangerous of snakes.</p>

<p class='c032'>Divided into two subfamilies, each of which is
represented by one genus in Europe:</p>

<p class='c032'><i>Viperinæ.</i>—No pit on the side of the snout;
maxillary bone not hollowed out.</p>

<p class='c032'><i>Crotalinæ.</i>—A deep pit on each side of the snout,
between the nostril and the eye; maxillary bone
hollowed out above.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p12'><i>PLATE XII</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_256a.jpg' width="400" height="119"
    alt=""/>
<p class='caption'>VIPERA URSINII<br />
<i>From Zoological Society’s Proceedings</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_256b.jpg' width="400" height="94"
    alt=""/>
<p class='caption'>VIPERA RENARDI<br />
<i>From Zoological Society’s Proceedings</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_256c.jpg' width="400" height="341"
    alt=""/>
<p class='caption'>VIPERA BERUS<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'>The <i>Viperinæ</i> inhabit nearly the whole of Europe,
<span class='pagenum'><a name='Page_221' id='Page_221'>221</a></span>
Asia, and Africa; the <i>Crotalinæ</i> are Asiatic (one
species extending its range into a small part of
South-Eastern Europe) and American.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus VIPERA, Laurenti</span>
  </div>
</div>

<p class='c032'>Head distinct from neck, covered with small
shields or scales, with or without distinct frontal and
parietal shields; eye moderate or small, with vertical
pupil, separated from the labial shields by scales;
nasal separated from the rostral by a naso-rostral.
Body short. Scales keeled, with apical pits. Tail
short.</p>

<p class='c032'>Of the eleven species of this genus, six are found in
Europe; two inhabit South-Western Asia, one the
Indo-Malay region, and two Eastern Africa.</p>

<p class='c032'>The distinction of the European species is one of
considerable difficulty, owing to their close relationship
and the presence of intermediate forms connecting
them. Matters being so, it seems curious that
the Common Adder should have been regarded by
so many authors as generically distinct from the
Asp Viper, under the name of <i>Pelias berus</i>. It is
highly probable that hybrids are produced in those
districts where two species coexist, as in some parts
of France, North Italy, and Austria.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    21. <span class='sc'>Vipera ursinii</span>, Bonaparte<br />
    Orsini’s Viper
  </div>
</div>

<p class='c032'><i>Form.</i>—Short and stout. Snout obtusely pointed,
flat above or with the canthus slightly raised. Eye
<span class='pagenum'><a name='Page_222' id='Page_222'>222</a></span>
very small, usually smaller than the nasal shield, its
horizontal diameter usually not exceeding its distance
from the posterior border of the nostril, its vertical
diameter often less than and rarely exceeding its
distance from the mouth. Length of tail seven to
eight times in total length in males, nine and a half
to twelve times in females.</p>

<p><a id='f33' name='f33' href='#f33'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_259.jpg' width="200" height="133"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 33</span> (From Proceedings of the Zoological
Society, 1893)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral as deep as broad or slightly
deeper than broad, visible from above, in contact
with one
apical shield
(rarely with
two). Distinct
frontal
and (usually)
parietal
shields, the
former once
and a half
to once and
two-thirds (rarely once and one-third) as long as
broad, as long as its distance from the rostral
or the end of the snout, and nearly always longer
than the parietals; the latter always in contact
with the former, rarely broken up into small
shields. Four to seven small shields on the snout
between the canthals, of which there are two on
each side. Supraocular well developed, extending
posteriorly beyond the vertical of the eye, separated
<span class='pagenum'><a name='Page_223' id='Page_223'>223</a></span>
from the frontal by one to three shields, very
rarely in contact with it. Six to ten scales round
the eye, usually eight or nine, the upper preocular
usually in contact with the nasal; a single
series of scales between the eye and the labials.
Nasal single. Temporal scales smooth. Upper
labials six to nine, usually seven or eight, usually
third or third and fourth below the eye. Three
(rarely four) lower labials in contact with the chin-shields,
of which there is but one pair.</p>

<p class='c032'><i>Scales</i> in nineteen (rarely twenty or twenty-one)
rows, with two apical pits, strongly keeled on the back,
less strongly on the sides, outer row smooth. Ventral
shields 120 to 135 in males, 125 to 142 in females; anal
entire; subcaudals 30 to 37 in males, 20 to 28 in
females. By adding the subcaudals to the ventrals in
a hundred specimens, the total numbers are 153 to 169
in males, 150 to 168 in females.</p>

<p class='c032'><i>Coloration.</i>—Unlike its ally <i>V. berus</i>, <i>V. ursinii</i>
shows no sexual differences in the coloration. The
ground colour of the back is usually yellowish or pale
brown, sharply defined from the darker grey or brown
colour of the sides; some specimens, however, are of
an almost uniform brown ground colour. The light
colour of the back is relieved by a series of more or
less regular transversely oval, elliptic, or rhomboidal
dark brown, black-edged spots, some or all of which
may run together to form a wavy or zigzag band
(<a href='#p12'>Plate XII</a>.). Two or three longitudinal series of dark
<span class='pagenum'><a name='Page_224' id='Page_224'>224</a></span>
brown or black spots extend along the sides, the upper
series, if present, occupying the space between the
series of spots continued from the postocular band
and the large dorsal spots or vertebral band, the
lowermost following the outer row of scales. Small
dark spots and one or two
<b>Λ</b>-shaped
markings are
present on the upper surface of the head; an oblique
dark band proceeds from the eye to the angle of the
mouth, and is not infrequently confluent with the
branches of the occipital
<b>Λ</b>.
The rostral and the
labial shields are uniform yellowish-white, rarely
with a few small, blackish spots or with brown
borders. The chin and throat are yellowish-white,
rarely with some blackish spots. The ventral and
subcaudal shields are black, with transverse series of
small white spots, or grey checkered with black and
white, or whitish with small round black spots; the
tail is but rarely (females) tipped with yellow.</p>

<p class='c032'>The form recently described as <i>V. macrops</i>, Méhely,
from Bosnia and Herzegovina, is distinguished by a
usually larger eye, the vertical diameter of which
equals or a little exceeds its distance from the mouth,
and the parietals are often broken up into small
shields. The postocular dark band is often reduced,
originating at some distance from the eye, and is not
prolonged beyond the mouth. In this geographical
race melanic specimens occasionally occur, which are
dark brown or blackish above, the lower parts not
differing from those of the typical form.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_225' id='Page_225'>225</a></span>
<i>Size.</i>—20 inches appears to be the usual maximum
size reached by this species, but, Dr. Werner informs
me, a female 2 feet long has been found in Lower
Austria.</p>

<p class='c032'><i>Distribution.</i>—First discovered in Italy in the
Abruzzi, this species has since been found in the
Basses-Alpes, near Digne, in various parts of Hungary,
in Lower Austria, on the island of Veglia in
Istria, and in Bosnia, Bulgaria, Herzegovina, and
Montenegro. A very broken and curious distribution,
the more so as <i>V. ursinii</i> is essentially a form of the
plain in Lower Austria and Hungary, and an alpine
form in Italy, in France, and in the Balkan Peninsula,
where it only occurs between 3,000 and 6,800
feet. In no part of its habitat does it appear ever to
be found in company with <i>V. berus</i>.</p>

<p class='c032'><i>Habits.</i>—Only a few specimens have hitherto been
found in Italy and in France, but the species occurred
up to a few years ago in extraordinary numbers in
Lower Austria, in the immediate vicinity of Laxenburg.
The intendant of the imperial castle pays a premium
for the destruction of Vipers, and in the course
of one year (1892) more than 1,000 specimens were
brought to him. These snakes are found principally,
though not exclusively, in the marshy meadows
around the park, where they may be seen about in
the daytime from May to September, feeding chiefly
on lizards (<i>Lacerta agilis</i>), and also on small rodents.
The lizards are swallowed as soon as seized, without
<span class='pagenum'><a name='Page_226' id='Page_226'>226</a></span>
the effect of the poison being awaited as in other
Viperid snakes. This Viper is as a rule of gentle
disposition, allowing itself to be handled without
attempting to bite, and village boys have been seen
playing with them. Although occurring in such
enormous numbers at Laxenburg, no accident from
snake-bite has ever been heard of. The form from
the Balkan Peninsula (<i>V. macrops</i>) is even more pacific
still, and is believed never to make use of its poison
apparatus, its food consisting of orthopterous insects.
According to Captain Veith, who has collected a large
number of specimens of this Southern form, the contents
of the stomach as well as the excrements show
this snake to feed exclusively on grasshoppers. On
one occasion a big specimen showed such a swelling
of the body as to lead to the conclusion that it had
swallowed a mouse, but it soon after disgorged what
proved to be a ball made up of the agglutinated
remains of at least a hundred grasshoppers. When
handled, this Viper hisses or even pretends to snap,
but with closed mouth, never biting unless seriously
hurt. The poison appears to have little effect on man.</p>

<p class='c032'><i>Reproduction.</i>—Nothing has been published on the
breeding habits of this species, but in a letter to
the author, dated January 14, 1913, Herr L.
von Kirchroth, who has examined over 4,000
specimens since 1890, says the young are born in
July or August, exceptionally as early as June.
Young females bring forth from six to eight young,
<span class='pagenum'><a name='Page_227' id='Page_227'>227</a></span>
older females from eight to eighteen; but a large
female from Lower Austria is reported to have contained
as many as twenty-two. The length of the
new-born young is from 5 to 6 inches, and it grows
rapidly within the first week, probably through
stretching out, without taking any food.</p>

<p class='c032'>According to Captain Veith, the form described as
<i>V. macrops</i> brings forth only from three to five
young.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    22. <span class='sc'>Vipera renardi</span>, Christoph<br />
    Renard’s Viper
  </div>
</div>

<p class='c032'><i>Form.</i>—Similar to the preceding species, but snout
more pointed, the raised canthi rostrales meeting at
an acute angle. Eye usually as large as in <i>V. berus</i>,
nearly as large as the nasal shield; its horizontal
diameter equal to its distance from the posterior or
anterior border of the nostril, its vertical diameter
equal to or a little less than its distance from the
mouth. Length of tail seven and a half to nine times
in total length in males, eight to ten times in
females.</p>

<p class='c032'><i>Head-Shields.</i>—Rostral as deep as broad or a little
deeper than broad, just visible from above, and in
contact with a single apical shield. Distinct frontal
and (usually) parietal shields, the former once and
two-thirds to twice and one-third as long as broad, as
long as or longer than its distance from the end of the
snout, usually longer than the parietals; the latter
<span class='pagenum'><a name='Page_228' id='Page_228'>228</a></span>
always in contact with the former, unless broken up
into small shields. Two to six, usually three or four,
small shields on the snout between the canthals, of
which there are two on each side, the second broadly
in contact with the supraocular. Supraocular well
developed, extending posteriorly beyond the vertical
of the eye, separated from the frontal by one to four
shields. Nine to eleven, usually ten, scales round
the eye, the upper preocular usually in contact with
the nasal; either
a single series of
scales between
the eye and the
labials, or two
series except
under the centre
of the eye, which
is separated
from the fourth
labial by a
single scale. Nasal single. Temporal scales all
smooth, or the upper faintly keeled. Upper labials,
eight or nine, fourth or fourth and fifth below
the eye. Four (rarely five) lower labials in contact
with the chin-shields, of which there is but one
pair.</p>

<p><a id='f34' name='f34' href='#f34'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_265.jpg' width="200" height="141"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 34</span> (From Proceedings of the Zoological
Society, 1893)</p>
</div>

<p class='c032'><i>Scales</i> in twenty-one (very rarely nineteen) rows, with
two apical pits, strongly keeled, outer row smooth or
feebly keeled. Ventral shields 130 to 148 in males,
<span class='pagenum'><a name='Page_229' id='Page_229'>229</a></span>
130 to 150 in females; anal entire; subcaudals 31 to
37 in males, 24 to 30 in females.</p>

<p class='c032'><i>Coloration.</i>—As in <i>V. ursinii</i>, the sexes are alike in
coloration. European specimens (<a href='#p12'>Plate XII</a>.) are very
similar to <i>V. ursinii</i>, except that the labial shields are
markedly dark-edged and speckled or spotted with
brown or black. The dorsal band or series of spots
is dark brown, edged with blackish; the ground
colour of the middle of the back and of the scales of
the two outer rows on each side is yellowish, of the
sides (four rows of scales) greyish-brown with two or
three series of dark brown spots; two dark
<b>Λ</b>-shaped
markings on the head; a dark postocular streak,
extending or not to the side of the neck. The lower
parts are whitish or pale greyish, with blackish dots,
of which there is a series of larger ones along each
side of the belly. The tip of the tail is never
yellow.</p>

<p class='c032'>Central Asian specimens are of a pale yellowish
sand-colour, with a brown, dark-edged dorsal zigzag
band or series of spots and two series of small spots
on the sides. Belly whitish, dotted or spotted with
black, or uniform blackish.</p>

<p class='c032'><i>Size.</i>—23 inches is the length of the largest
specimen examined.</p>

<p class='c032'><i>Distribution.</i>—In Europe <i>V. renardi</i>, which has
long been confounded with <i>V. berus</i>, is abundant in
the district of Uralsk, in the steppe around Sarepta,
in Crimea, and it is also found in Cis-Caucasia and
<span class='pagenum'><a name='Page_230' id='Page_230'>230</a></span>
in Bessarabia. Its range extends far into Central
Asia, being known from the Khirghiz steppes, the
Emba steppes, the steppes near the Alatau, on the
borders of the Urdshar, and in the Semipolatinsk
district. Around Sarepta it is common in the bare
steppe, and only exceptionally occurs in localities
overgrown with willows and small shrubs.</p>

<p class='c032'><i>Habits.</i>—Nothing has been published concerning
the habits of this snake, except that it is more sensitive
to cold than <i>V. berus</i> and does not appear before the
middle of April, retiring to its winter-quarters in the
beginning of October. The food consists of small
mammals and lizards.</p>

<p class='c032'><i>Reproduction.</i>—Pairs in May, and brings forth five
to seven young in August, these young at birth
measuring about
5<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    23. <span class='sc'>Vipera berus</span>, Linnæus<br />
    The Northern Viper, or Adder
  </div>
</div>

<p class='c032'><i>Form.</i>—Short and stout. Snout flat above, rarely
slightly concave, the upper contour broadly rounded
or truncate in front, the canthus well marked, sometimes
slightly raised, the loreal region nearly vertical.
Eye as a rule smaller in females than in males, as
large or nearly as large as the nasal shield; its
vertical diameter equals or a little exceeds its distance
from the mouth. Length of tail five and a
half to nine times in total length in males, eight to
ten and three-quarter times in females.</p>

<p><span class='pagenum'><a name='Page_231' id='Page_231'>231</a></span></p>
<p><a id='f35' name='f35' href='#f35'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_268.jpg' width="200" height="147"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 35</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral as deep as broad or slightly
broader than deep, rarely once and one-third as deep
as broad, not or but scarcely visible from above. In
addition to the supraoculars, three large shields, the
frontal and the parietals, are as a rule present on
the top of the head. Frontal as long as broad or a
little longer than broad, rarely much longer than
broad, once and a half to twice and a half as broad
as the supraocular, from which it is as a rule separated
by one to four
shields, as long
as or a little
shorter than its
distance from the
rostral, as long as
or a little shorter
than the parietals.
Parietals usually
in contact with
the frontal and separated from the supraoculars
by small shields, but sometimes in contact with
both, or separated from the frontal. Exceptionally,
in specimens from Great Britain, Germany,
and Austria, the parietals, or the frontal and the
parietals, are broken up into scales, and this is more
frequently the case in specimens from North-Western
Spain (var. <i>seoanei</i>). Upper surface of snout bordered
by six (rarely by five or four) small shields, viz.,
two apicals (rarely one), and on each side two canthals,
<span class='pagenum'><a name='Page_232' id='Page_232'>232</a></span>
the second of which is usually in contact with
the supraocular; canthals very rarely united into one
shield; the space between these shields covered by
four to twenty flat or convex, juxtaposed scales,
which very exceptionally are fused into a single
large shield. Supraocular usually extending posteriorly
beyond the vertical of the eye. Six to thirteen
scales round the eye, usually eight to ten; two
or three superposed scales, rarely two vertical series
of scales, separate the preoculars from the nasal,
which is single. As a rule a single series of scales
intervenes between the eye and the labials; specimens
with two series are of very exceptional occurrence
(single specimens from Isle of Arran, Normandy,
Southern Norway, and Carniola, in the British
Museum), but there are occasionally two series
except just below the centre of the eye. Upper labials
six to ten, usually eight or nine; fourth or fourth
and fifth (rarely third and fourth) below the eye.
Temporal scales smooth, rarely feebly keeled. Three
or four (rarely five) lower labials in contact with
the single pair of chin-shields.</p>

<p class='c032'><i>Scales</i> in twenty-one (rarely nineteen or twenty-three)
rows, with two apical pits, strongly keeled,
those of the outer row smooth or feebly keeled.
Ventral shields 132 to 150 (usually 137 to 147) in
males, 132 to 158 (usually 140 to 150) in females;
anal entire; subcaudals 32 to 46 (usually 35 to 40)
in males, 24 to 38 (usually 28 to 33) in females.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_233' id='Page_233'>233</a></span>
<i>Coloration.</i>—It is characteristic of this species,
contrary to the rule in snakes, to present such
marked differences of colour, according to the sexes,
that these can be distinguished in most cases from
that character alone.</p>

<p class='c032'>Whitish or pale grey specimens, with black belly
and jet black dorsal markings (<a href='#p12'>Plate XII</a>.), are males.
Brown and brick-red specimens, with the markings
of a more or less dark brown or red, are females.
There are also brown, reddish-brown or olive males
with the markings of a deep black, and grey males
with brown markings. A very pretty colour variety,
which affects only females, is olive with brick-red
band and spots. Some males, just before exuviation,
have the lower surface of a pale greyish-blue
(<i>Coluber cæruleus</i>, Sheppard), with the outer ends of
the shields black. Specimens with yellowish-white
chin and throat, which may be tinged with red, are
females; males have the throat black, or whitish with
the scales spotted or edged with black. Exceptional
females occur (in Carniola) which in this respect resemble
the males.</p>

<p class='c032'>The markings vary considerably. Those on the back
usually consist of a wavy or zigzag longitudinal band,
flanked on each side with a series of spots corresponding
to its sinuses; but this band may be partly
or even entirely broken up into rhomboidal or transversely
oval spots, or, losing its indentations, form a
straight stripe edged on each side with a yellowish
<span class='pagenum'><a name='Page_234' id='Page_234'>234</a></span>
streak (as in some specimens of the var. <i>seoanei</i>, from
North-Western Spain). The markings may be absent
altogether (var. <i>concolor</i>, Jan), or reduced to a narrow
straight vertebral band (<i>Pelias dorsalis</i>, Gray). In
the var. <i>seoanei</i> the zigzag band is often replaced by
a dark brown vertebral band, three to five scales
wide, bordered on each side by a series of subtriangular
or crescentic black spots opposite to each other,
as in the Pyrenean specimens of <i>V. aspis</i>. A pair of
elongate dark markings are usually present on the
back of the head, affecting the following shapes:
<b>|\,)(,)(,)(;</b> By uniting together, this pair of markings
may form a
<b>Λ</b>
or an <b>X</b>. An oblique dark streak
extends on each side from the eye to the last labial
shields, being sometimes prolonged a short way down
the neck. The snout and vertex may be uniform or
bear some symmetrical dark spots, or in some males
be entirely black, the black involving the apex of the
<b>Λ</b>-shaped
marking. The labial shields are whitish or
yellowish, those at least which are anterior to the
eye being more or less broadly edged with brown or
black.</p>

<p class='c032'>The belly and the lower surface of the tail vary
from grey or brown to bluish, blackish-grey, or black,
the sides usually dotted or spotted with whitish;
sometimes, especially in females, the belly is dark
grey, each shield with a white posterior border which
is broken up by a series of small roundish black spots.
The end of the tail is often yellowish, bright yellow,
<span class='pagenum'><a name='Page_235' id='Page_235'>235</a></span>
or pale orange below, rarely coral red, more commonly
in females than in males.</p>

<p class='c032'>The iris is usually coppery red, more rarely golden
suffused with brown.</p>

<p class='c032'>Black specimens occur, more or less frequently, all
over the habitat of this species, and are often referred
to as <i>V. prester</i>, Linnæus. A distinction has to be
made between individuals which are black through
darkening of the ground colour, and such as are thus
coloured through expansion and confluence of the
markings. The latter are males, and among them
we may find intermediate stages showing how this
melanism is brought about; in one case the black of
the back is separated from the black of the sides by
a narrow light brown wavy stripe, the remains of
the ground colour. When, as in all females, and
occasionally in males, the black is the result of a
gradual darkening of the ground colour, the typical
markings may still be detected under certain lights.
Some specimens (from Schneeberg, Lower Austria)
are black, with scattered golden dots, or of a dark
mahogany brown speckled with yellowish. In
nearly all the black specimens at least a few dots of
whitish are visible on the lips, and of yellow under
the end of the tail.</p>

<p class='c032'>Most of the variations enumerated above occur irrespective
of the geographical distribution. Two forms,
however, deserve to be regarded as ill-defined local
races: the var. <i>seoanei</i>, Lataste, from North-Western
<span class='pagenum'><a name='Page_236' id='Page_236'>236</a></span>
Spain, in which, in addition to the peculiarities of
coloration mentioned in the description, the canthus
rostralis is frequently more distinctly raised, and the
frontal and parietal shields are often disintegrated
into scales; and the var. <i>bosniensis</i>, Boettger, from
Bosnia, Carniola, and Carinthia, which is sometimes
very suggestive of, and has been taken for, the typical
form of <i>V. aspis</i>, having like it, though not at all
constantly, two series of scales between the eye and
the labials, and the zigzag band replaced by a series
of dark bars across the back. The var. <i>pseudaspis</i>,
Schreiber, from the plains of Sclavonia, described
as straw yellow above, with narrow dark cross-bars,
is hardly separable from the var. <i>bosniensis</i>.</p>

<p class='c032'><i>Size.</i>—<i>Vipera berus</i> is said to reach very exceptionally
a length of 2 feet 11 inches. The largest
specimen in the British Museum (from Belgium)
measures 2 feet
3<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches: the largest British
specimen 2 feet 3 inches. Both these specimens are
females. The largest male measures 2 feet 2 inches.</p>

<p class='c032'><i>Distribution.</i>—<i>Vipera berus</i> ranges over the whole
of Northern Europe, to the extreme north of Scotland,
and the sixty-seventh degree in Scandinavia,
and right across Northern Asia as far east as the
island of Saghalien. It is generally distributed in
Great Britain, occurring also on the Isles of Arran,
Islay, Skye, Lewis, and Mull, rare or absent in
some districts, common in others. Its distribution
in Central and Southern Europe is irregular. In
<span class='pagenum'><a name='Page_237' id='Page_237'>237</a></span>
Western France it does not extend much beyond the
Loire to the south, only isolated captures being on
record from the departments Vendée, Deux-Sèvres,
Vienne, and Indre. Of rare occurrence south of
Paris, in the departments Yonne and Allier and in
the mountains of Auvergne, it is again abundant in
some parts of the Central Plateau. To the east it
is recorded from the departments Aude, Haute-Marne,
and Vosges. In Belgium, it is known from
Flanders, Limburg, the Meuse Valley, and the
Ardennes; in Holland it is pretty generally distributed
in the uncultivated parts. It is spread over
nearly the whole of the German Empire with the
exception of the vine districts, where it is absent or
extremely rare; it is also very scarce in the mountains
of the Black Forest; it is on record from only a few
localities in Lorraine, and has never been found in
Alsatia. In South Germany it is rarely found below
1,000 feet altitude. In Switzerland it is absent from
the Jura, but occurs in the Alps chiefly between
2,500 and 9,000 feet. To the East it extends to
Russia, as far north as 64°, Austria-Hungary, confined
to the hills in the south, and Roumania.
In the Balkan Peninsula it occurs in the mountains
of Bosnia, of Herzegovina, and of Bulgaria, up to
7,000 feet. Absent from the South of France, it
curiously reappears in the hills of the north coast of
Spain, even at sea-level in Galicia, and in a few
localities in North Portugal. On the southern side
<span class='pagenum'><a name='Page_238' id='Page_238'>238</a></span>
of the Alps it is much rarer than <i>V. aspis</i>, but it has
established itself in a few low-lying districts in
Lombardy, Venetia, and the neighbouring part of
Emilia.</p>

<p class='c032'><i>Habits.</i>—As we see from the above sketch of
its distribution, the Adder generally avoids the
hotter parts of Europe; when found in the plain
in the South, as in Italy, it dwells in marshy
localities, and Bonaparte called it <i>Marasso palustre</i>
(Marsh Viper) in opposition to his <i>Marasso alpino</i>,
<i>Vipera ursinii</i>. In the North, however, it usually
selects in preference dry moors, sandy heaths, and
hills well exposed to the sun, in which, although to
a certain extent a nocturnal reptile, it delights to
bask. Its food is very varied: weasels, mice, voles,
shrews, moles, birds, lizards, slow-worms, frogs,
salamanders, large slugs, have been found in the
stomach, and the very young feed also on insects
and worms. Of irascible temper as a rule, Adders
are very ready to bite when fresh caught, but
instances are known of their becoming quite tame
in captivity, allowing themselves to be handled.
As a rule they refuse food in captivity, but some
have been known to live for as long as five years,
being fed on lizards. Accidents from their bite,
although seldom heard of in this country, are of
frequent occurrence in France and in Germany,
where many cases of fatal results on people have
been recorded.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_239' id='Page_239'>239</a></span>
<i>Reproduction.</i>—Pairing takes place in April and
May, and the young, five to twenty in number, are
born in August or September, exceptionally as early
as the end of July; the young, on releasing themselves
from the thin, transparent membrane in which
they are enclosed at birth, measure 6 to 8 inches.
According to J. Geithe, a black female from Saxony
gave birth to seventeen young, of which only one, a
male, was black.</p>

<p class='c032'>It is probable that exceptionally some individuals
pair late in the summer or in the autumn. There is
a trustworthy record, by Eiffe, of three pregnant
females having been caught near Hamburg on
March 12, 1882, one of them giving birth to young
on the following day.</p>

<p class='c032'>Dicephalous young have occasionally been observed.
One 6 inches long was found crawling in a field near
Hornburg in Germany in October, 1895, and, having
been kept alive for some time, was observed to hiss
and open the two mouths alternately when taking
up a defensive attitude. Another similar monster,
from Cornwall, is reported to have been sent alive to
the London Zoological Gardens in 1854.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    24. <span class='sc'>Vipera aspis</span>, Linnæus<br />
    The Asp Viper
  </div>
</div>

<p class='c032'><i>Form.</i>—Rather more elongate than in the preceding.
Snout flat above, more or less distinctly turned
up at the end, with sharp, not or but very slightly
<span class='pagenum'><a name='Page_240' id='Page_240'>240</a></span>
raised canthus, and vertical or nearly vertical loreal
region. Vertical diameter of the eye equal to or a
little less than its distance from the mouth. The
raised upper border of the transversely truncate or
obtusely pointed extremity of the snout, coupled
with the downward slant of the supraocular region
and canthus rostralis, gives the head, seen from the
side, a peculiar expression; the eye is so oblique
that a vertical line drawn from the posterior extremity
of the supraocular
shield to the lip
usually passes
through the eye
or down its posterior
border; but
the extent to which
the snout is turned
up at the end
varies considerably,
some specimens approaching <i>V. berus</i> in this
respect, others <i>V. latastii</i>. Length of tail five and a
half to eight times in total length in males, seven to
nine times in females.</p>

<p><a id='f36' name='f36' href='#f36'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_277.jpg' width="200" height="151"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 36</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral deeper than broad, its width
two-thirds to seven-eighths its depth, extending to the
upper edge of the snout. As a rule, with the exception
of the large supraocular, the upper surface of the head
is covered with small, subimbricate scales, which are
smooth, very rarely feebly keeled, between the eyes
<span class='pagenum'><a name='Page_241' id='Page_241'>241</a></span>
and on the snout; however, an enlarged frontal
shield, or even a frontal and a pair of parietals, are
sometimes present, though rarely so large as in
a typical <i>V. berus</i>; when present, the frontal is
separated from the supraocular by one or two series
of scales; when the frontal is absent, four to seven
series of scales separate the supraoculars. Upper
surface of snout usually bordered by eight or nine
small shields—viz., two or three apicals, in contact
with the tip of the rostral and raised to form the
turned-up nose, and, on each side, two canthals and
the upper preocular, which separates the supraocular
from the canthals, or three canthals; sometimes,
however, the border is formed by six or seven
small shields, the second canthal being in contact
with the supraocular, as in <i>V. berus</i>. Supraocular
usually with very convex outer border, not extending
posteriorly beyond the vertical of the eye. Eight to
thirteen scales round the eye, usually ten to twelve;
one or two vertical series of scales separate the preoculars
from the nasal, which is single or divided,
and often rather deeply hollowed out. As a rule
two series of scales (very rarely three) separate the
eye from the labials; sometimes, however, there is
but one scale between the eye and the fourth labial,
the second series being incomplete. Upper labials
nine to thirteen, usually nine to eleven, fourth and
fifth, rarely fourth to sixth or fifth and sixth, below
the eye. Temporal scales smooth or feebly keeled.
<span class='pagenum'><a name='Page_242' id='Page_242'>242</a></span>
Four (rarely five) lower labials in contact with the
single pair of chin-shields.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p13'><i>PLATE XIII</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_278a.jpg' width="250" height="195"
    alt=""/>
<p class='caption'>VIPERA ASPIS<br />
<i>After Calmette</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_278b.jpg' width="400" height="272"
    alt=""/>
<p class='caption'>VIPERA LATASTII</p>
</div>

<p class='c032'><i>Scales</i> in twenty-one or twenty-three (rarely nineteen
or twenty-five) rows, with two apical pits,
strongly keeled, those of the outer row more or less
distinctly keeled, rarely perfectly smooth. Ventral
shields 134 to 158 (usually 143 to 153) in males,
141 to 169 (usually 145 to 157) in females; anal
entire; subcaudals 32 to 49 (usually 37 to 45) in
males, 30 to 43 (usually 32 to 38) in females; the
terminal caudal shield is sometimes shorter and less
spine-like than in <i>V. berus</i>, quite obtuse in some
specimens.</p>

<p class='c032'><i>Coloration.</i>—Grey, greyish-brown, brown, reddish-brown,
coppery red, or orange, is the ground colour
in individuals from the same district; in this
respect sexual differences are less marked than in
the preceding species, red or copper-coloured specimens
being found in both sexes, and silvery white
specimens do not seem ever to occur. In rare cases
markings are entirely absent. In specimens from
the greater part of France, Italy, and the Southern
Tyrol (see <a href='#p13'>Plate XIII</a>.), the dark brown or black
markings on the body are mostly in the form of
narrow cross-bars, continuous across the back or
broken on the vertebral line and often alternating
with each other and with similar bars on the sides,
thus producing a pattern not unlike that frequently
found in <i>Tropidonotus natrix</i>; a narrow dark line
<span class='pagenum'><a name='Page_243' id='Page_243'>243</a></span>
running straight or zigzag along the spine may
connect these cross-bars, and in rare cases it is so
broad as to produce a zigzag band similar to that of
<i>V. berus</i>. In specimens from South-Western France
and the Pyrenees, rarely in some from other parts of
France and Italy, there is a broad dark grey or
brown vertebral band between two series of black or
blackish-brown spots, opposite to each other or
alternating; this band may be straight or wavy, sometimes
forming a regular zigzag; there is another
series of blackish spots or short bars lower down on
the side, alternating with those of the dorsal series.</p>

<p class='c032'>The upper surface of the head may be devoid of
any markings, or bear merely the two oblique dark
streaks forming the branches of a
<b>Λ</b>;
or a dark
cross-bar may be present on the snout, followed or
not by smaller spots or a pair of oblique streaks on
the occiput; the
<b>Λ</b>
on the back of the head may
be united with the first cross-bar on the nape, and
enclose a cordiform figure of the lighter ground
colour. A light line sometimes borders the upper
edge of the snout and the outer edge of the supraocular
shield. A blackish band or a mere line
extends obliquely from the eye to the first lateral
spot; below this the upper lip is whitish, yellowish,
or pinkish, with or without dark vertical bars on the
sutures between the labial shields. The iris is
golden or coppery red.</p>

<p class='c032'>The lower parts vary as much as the upper:
<span class='pagenum'><a name='Page_244' id='Page_244'>244</a></span>
sometimes black or steel blue, with or without whitish
or reddish dots or spots, sometimes yellowish or
pale reddish, with brown dots or marblings; in
some young, white with greyish dots. The throat
is yellowish white or pale reddish, uniform or
speckled with blackish, sometimes (males) nearly
entirely black. The end of the tail is usually bright
yellow or reddish, or at least with a few bright spots.
And finally we must mention black specimens—some
nearly black by darkening of the ground colour,
others intensely black by enlargement of the markings.
A specimen from Piedmont, in the Turin
Museum, shows the ground colour reduced to mere
narrow light bars disposed in pairs. In most of
these black specimens the chin and throat remain
entirely or partially yellowish or reddish, and a few
spots of the same colour are to be seen under the
end of the tail.</p>

<p class='c032'>A remarkable form of <i>V. aspis</i>, which some herpetologists
would perhaps regard as entitled to rank as
a species, is the var. <i>hugyi</i>, Schinz, from Calabria
and Sicily. It is in some respects intermediate
between <i>V. aspis</i> and <i>V. latastii</i>. The snout is rather
more pointed than usual in the typical form,
often, though not constantly, more strongly turned
up at the end, and the canthus rostralis may be
distinctly raised. Constantly two canthal shields,
the second in contact with the supraocular. Ventral
shields 134 to 148; subcaudals 30 to 43. Pale
<span class='pagenum'><a name='Page_245' id='Page_245'>245</a></span>
greyish, yellowish, brownish, or reddish, above, with
a broad wavy dark brown vertebral band, edged
with darker; this band sometimes broken up into
transversely oval spots; a lateral series of blackish-brown
spots, each corresponding to the sinus of the
dorsal band.</p>

<p class='c032'>Specimens so completely intermediate between
<i>Vipera aspis</i> and <i>V. berus</i> as to render their naming
arbitrary are known from parts of France and Italy
where the two species coexist, and are probably to
be regarded as hybrids.</p>

<p class='c032'><i>Size.</i>—The largest specimen examined (St. Sever,
Landes, in the Lataste Collection) measures 2 feet
2<span class='nom'>1</span>⁄<span class='dem'>2</span>
inches. It is a male. The largest female in the
British Museum is 2 inches shorter.</p>

<p class='c032'><i>Distribution.</i>—<i>Vipera aspis</i> is found over the whole
of France south of a line connecting the departments
Loire-Inférieure, Orne, Seine-et-Marne, and
Meurthe-et-Moselle, and ascends the Pyrenees to
the altitude of 7,250 feet. In Germany it is known
from Lorraine and the Black Forest, in Switzerland
from the western and southern parts, up to 5,000
feet on the northern side of the Alps. It occurs
also in Austria, in the Southern Tyrol and in the
Karst, and is distributed over the whole of Italy and
Sicily, reaching an altitude of 9,700 feet in the
Alps. Most of the specimens from the western parts
of the Balkan Peninsula which have been referred
to this species belong, apparently, to <i>V. berus</i>, var.
<span class='pagenum'><a name='Page_246' id='Page_246'>246</a></span>
<i>bosniensis</i>, but one from Jahorin in Bosnia, altitude
5,650 feet, preserved in the Bosnian Museum, is pronounced
by Werner to be an unquestionable <i>V. aspis</i>.</p>

<p class='c032'><i>Habits.</i>—This Viper shows a predilection for hot
and dry localities. It is both diurnal and nocturnal,
and does not seem to wander far from its hole in a
rock or in the earth. It is slow in its movements,
but very irascible, and innumerable accidents, in
some cases fatal to man, are caused yearly in many
parts of France, where it is extremely abundant.
Its food consists principally of small mammals,
young birds, and lizards, but the very young eat
insects and worms. In France it retires into its
winter-quarters at the end of October or in November,
and numerous specimens often congregate in
the same hole; it resumes its activity towards the
end of March or the beginning of April, sometimes
as early as the end of February. In rare cases it
will even leave its retreat in the middle of winter, to
bask in the sun. In captivity it long retains its
savage temper, and usually refuses all food.</p>

<p class='c032'><i>Reproduction.</i>—<i>Vipera aspis</i> pairs in April and May;
the pair are entwined in each other’s coils. The
young, four to eighteen in number, but rarely more
than ten, are born in August or September, and
measure 7 or 8 inches.</p>

<p class='c032'>Several cases of dicephaly in young specimens
have been described.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >

<span class='pagenum'><a name='Page_247' id='Page_247'>247</a></span>
25. <span class='sc'>Vipera latastii</span>, Bosca<br />
    Lataste’s Viper
  </div>
</div>

<p class='c032'><i>Form.</i>—Heavier than in the preceding. Head
similar, but snout more pointed and loreal region
slanting towards the lip, well visible when the head
is viewed from above. The extent to which the
snout is turned up at the end varies considerably,
sometimes similar to certain specimens of <i>V. aspis</i>,
sometimes forming an appendage which is only a
little less developed than in <i>V. ammodytes</i>. Length of
tail six and a half to seven and a half times in total
length in males, seven and a half to nine times in
females.</p>

<p><a id='f37' name='f37' href='#f37'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_286.jpg' width="200" height="121"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 37</span></p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral once and a half to twice as
deep as broad, nearly reaching the tip of the rostral
wart. Upper surface of head covered with small,
smooth or feebly keeled, subimbricate scales, among
which a slightly enlarged frontal, or a frontal and a
<span class='pagenum'><a name='Page_248' id='Page_248'>248</a></span>
pair of parietals, may sometimes be distinguished;
four to seven longitudinal series of scales between
the supraoculars, which are large, and do not as a
rule extend posteriorly beyond the vertical of the
eye. Five or six (rarely three) scales on the posterior
aspect of the raised part of the snout; two canthal
scales on each side, the second in contact with the
supraocular, or separated from it by the uppermost
preocular. Eight to thirteen (usually nine to twelve)
scales round the eye; two or three series of scales
between the eye and the labials. Nasal hollowed
out, entire, separated from the preoculars by one or
two vertical series of scales; naso-rostral sometimes
divided into two in North African specimens.
Temporal scales smooth or feebly keeled. Upper
labials nine to eleven (rarely eight), fourth and fifth
(rarely third and fourth) below the eye. Four or five
lower labials in contact with the single pair of chin-shields.</p>

<p class='c032'><i>Scales</i> in twenty-one rows, with two apical pits,
strongly keeled, outer row smooth or feebly keeled.
Ventral shields 125 to 146 in males, 135 to 147 in
females; anal entire; subcaudals 35 to 45 in males,
32 to 38 in females.</p>

<p class='c032'><i>Coloration.</i>—Grey or brown above, the back often
paler than the sides, with a broad darker, usually
black-edged, wavy or zigzag band along the spine, and
a lateral series of spots (<a href='#p13'>Plate XIII</a>.); the band sometimes
replaced by large rhombic or transversely oval
<span class='pagenum'><a name='Page_249' id='Page_249'>249</a></span>
spots. Head with or without dark markings above,
sometimes with two oblique dark streaks on the
occiput; a dark streak from behind the eye to the first
lateral spot, sometimes originating at a considerable
distance from the eye; upper lip white or pale
brown, more or less speckled or spotted with black.
Lower parts grey, spotted with black and white, or
blackish speckled with white, the end of the tail
usually yellow or with yellow spots.</p>

<p class='c032'><i>Size.</i>—This Viper is not known to exceed a length
of 2 feet.</p>

<p class='c032'><i>Distribution.</i>—Locally distributed over the greater
part of Spain and Portugal, as far north as Burgos
and Barcelona. Also found in Morocco near Tangier,
and in Algeria near Bona and Guyotville.</p>

<p class='c032'><i>Habits.</i>—Lataste’s Viper lives in stony and arid
districts, and also in forests. The food consists
chiefly of small mammals, but remains of a scorpion
have been found in the stomach of an adult, and of a
centipede in that of a young. According to Graells,
this Viper easily climbs low trees in search of young
birds, five of which have been found in the stomach
of one specimen. The bite is believed to be less
dangerous than that of <i>V. aspis</i>, and rarely causes
the death of man and domestic animals.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    26. <span class='sc'>Vipera ammodytes</span>, Linnæus<br />
    The Sand-Viper, or Long-Nosed Viper
  </div>
</div>

<p class='c032'>This species may be divided into several geographical
forms. The typical form will be described first.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_250' id='Page_250'>250</a></span>
<i>Form.</i>—Short and heavy. Snout pointed, produced
into an erect, horn-like dermal appendage
covered with scales; canthus rostralis strong, sometimes
slightly raised, loreal region slanting more or
less towards the lip. Vertical diameter of the eye
less than its distance from the mouth in the adult.
Length of tail six to nine and a half times in the total
length in males, eight to eleven times in females.</p>

<p><a id='f38' name='f38' href='#f38'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_289.jpg' width="200" height="131"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 38</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral usually broader than
deep. Naso-rostral (rarely divided into two) usually
reaching the
canthus rostralis,
and extending
considerably
higher up than
the upper border
of the rostral.
Rostral appendage
covered with
ten to seventeen
scales, arranged in three (rarely two or four) transverse
series between the rostral shield and the apex.
Upper surface of head covered with small smooth or
faintly keeled, subimbricate scales, among which a
feebly enlarged frontal shield or a frontal and a pair
of parietals are rarely distinguishable; when present,
the frontal is separated from the supraocular by two
series of scales; on the vertex five to eight series of
scales separate the supraoculars. Two (rarely three)
<span class='pagenum'><a name='Page_251' id='Page_251'>251</a></span>
canthal scales, the second separated from the supraocular
by the upper preocular. Supraocular with
very convex outer border, usually not extending
posteriorly beyond the vertical of the eye. Ten to
thirteen scales round the eye; one or two vertical
series of scales separate the preoculars from the
nasal, which is single or rarely divided, and hollowed
out. Two series of scales between the eye and the
labials. Upper labials eight to twelve, usually nine
or ten, usually fourth and fifth below the eye.
Temporal scales smooth or feebly keeled. Four or
five lower labials in contact with the single pair of
chin-shields.</p>

<div class='nf-right-c0'>
<div class='nf-right c040'  >
    <a id='p14'><i>PLATE XIV</i></a>
  </div>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_290a.jpg' width="400" height="103"
    alt=""/>
<p class='caption'>VIPERA LEBETINA<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_290b.jpg' width="400" height="294"
    alt=""/>
<p class='caption'>VIPERA AMMODYTES<br />
<i>After Sordelli</i></p>
</div>

<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_290c.jpg' width="400" height="96"
    alt=""/>
<p class='caption'>ANCISTRODON HALYS<br />
<i>After Sordelli</i></p>
</div>

<p class='c032'><i>Scales</i> in twenty-one or twenty-three (rarely twenty-five)
rows, with two apical pits, strongly keeled, those
of the outer row smooth or feebly keeled. Ventral
shields 143 to 161 in males, 147 to 160 in females;
anal entire; subcaudals 27 to 40 in males, 24 to 37
in females.</p>

<p class='c032'><i>Coloration.</i>—Grey, pinkish-grey, brown, yellowish-brown,
or brick red above, with a more or less
distinct wavy or zigzag black or brown, usually
black-edged, band along the back, or a series of large
rhombs connected on the median line, with or without
a lateral series of dark spots; specimens with the
markings of an intense black are males (<a href='#p14'>Plate XIV</a>.).
Head with or without dark markings, very variable
in disposition, sometimes forming a
<b>Λ</b>
on the occiput,
or a lyre-shaped figure confluent with the dorsal
<span class='pagenum'><a name='Page_252' id='Page_252'>252</a></span>
band; a dark streak or broad band from the eye to
the angle of the mouth, sometimes continued along
the neck; dark vertical bars often present on the
sides of the snout and under the eye; on the lower
lip, the dark shade, if present, broken up by light
bars separated by two to four labial shields. Belly
greyish or pink, powdered with brown or black, or
dark bluish-grey, with or without black and white
spots; lower surface of end of tail orange or coral
red, rarely yellow. Iris golden. Specimens with a
straight brown vertebral band flanked with triangular
black spots pointing outwards (var. <i>steindachneri</i>,
Werner) are known from Hungary, and resemble
certain colour varieties of <i>V. berus</i> and <i>V. aspis</i>.
Black specimens are very rare.</p>

<p class='c032'>The following varieties are important geographical
forms occurring in Europe:</p>

<p class='c032'>Var. <i>montandoni</i>, Boulenger: Naso-rostral shield
never reaching the canthus rostralis nor the summit
of the rostral shield, which is deeper than broad
(once and one-seventh to once and a half); rostral
appendage clad with ten to fourteen scales, in three
(rarely two or four) transverse series between the
rostral shield and the apex. Scales in twenty-one
rows. Ventral shields 149 to 158; subcaudals
30 to 38. A more or less distinct dark blotch on
the lower lip, involving five to seven labial shields
without complete interruption. Lower surface of
end of tail yellow.</p>

<p><span class='pagenum'><a name='Page_253' id='Page_253'>253</a></span></p>
<p><a id='f39' name='f39' href='#f39'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_294a.jpg' width="300" height="117"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 39</span>—<span class='sc'>Side Views of Heads of</span> <i>V. ammodytes typica</i> (<i>a</i>) <span class='sc'>and
Var.</span> <i>meridionalis</i> (<i>b</i>)</p>
</div>
<p><a id='f40' name='f40' href='#f40'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_294b.jpg' width="300" height="86"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 40</span>—<span class='sc'>Front Views of End of Snout, showing the Lepidosis.</span>
(From Proceedings of the Zoological Society, 1903)<br />
<i>a</i>, Form <i>typica</i>; <i>b</i>, var. <i>meridionalis</i>; <i>c</i>, var. <i>montandoni</i>
</p>
</div>

<p class='c032'>Var. <i>meridionalis</i>, Boulenger: Naso-rostral shield
never reaching the canthus rostralis, and but rarely
extending higher up than the upper border of the
rostral, which is often as deep as broad or a little
deeper than broad; rostral appendage clad with
fourteen to twenty scales, in four or five (rarely three)
transverse series between the rostral shield and the
apex. Supraciliary edge usually more prominent
than in the typical form, sometimes slightly angular.
Scales in twenty-one rows (very rarely twenty-three).
Ventral shields 133 to 147; subcaudals 24 to 35.
<span class='pagenum'><a name='Page_254' id='Page_254'>254</a></span>
A more or less distinct dark blotch on the lower lip,
involving five or six labial shields without interruption.
Lower surface of end of tail yellow.</p>

<p class='c032'><i>Size.</i>—This Viper exceptionally attains a length
of 3 feet. The largest male in the British Museum
measures 2 feet 6 inches, the largest female 2 feet
4 inches. In <i>V. berus</i> females grow to a larger size
than males; in this species, as in <i>V. aspis</i>, the reverse
appears to be the rule.</p>

<p class='c032'><i>Hybrid.</i>—A female specimen, presumed to be a
hybrid between <i>V. berus</i> and <i>V. ammodytes</i>, was
obtained by Captain Veith in 1902 in Carinthia, in
a locality where both these species occur together.
The shape of the head is exactly that of a typical
<i>V. aspis</i>, the snout distinctly turned up at the end,
but without wart or scaly appendage, the raised
portion being covered by the apex of the rostral
shield and three apical shields. The rostral shield,
which is a little deeper than broad (5&nbsp;:&nbsp;4), extends
above the level of the slightly raised canthus
rostralis, which bears two shields, the second in
contact with the supraocular. The naso-rostral
extends to the canthus rostralis, where it joins the
first canthal and the lateral apical shield; one series
of scales between the nasal shield and the preoculars.
On the upper surface of the head the snout is
covered with fifteen subimbricate smooth scales,
in addition to the canthals and apicals. A frontal
shield and a pair of parietals are well developed,
<span class='pagenum'><a name='Page_255' id='Page_255'>255</a></span>
although smaller than in an average <i>V. berus</i>; the
parietals are in contact with the frontal, between
which and the supraoculars two series of scales
intervene. The supraocular, as in <i>V. berus</i>, extends
backwards considerably beyond the vertical
of the eye. Eleven scales round the eye; two series
of scales between the eye and the labials. Temporal
scales smooth. Upper labials nine, fourth and fifth
below the eye. Scales in twenty-one rows, outer
row smooth. Ventrals 159; subcaudals 31.</p>

<p class='c032'>Grey-brown above, with a reddish-brown or
mahogany-coloured zigzag vertebral band and a
lateral series of paler reddish-brown spots; temporal
band ill-defined in front; no markings on the upper
surface of the head; lips pinkish, with a few reddish-brown
spots. Ventral shields pale brownish, finely
speckled or powdered with blackish, and with small
whitish spots on the free edge and reddish brown spots
on the sides. Tail orange red below. Iris fire
red.</p>

<p class='c032'>Total length 2 feet
2<span class='nom'>1</span>⁄<span class='dem'>3</span>
inches; tail
2<span class='nom'>2</span>⁄<span class='dem'>3</span>
inches.</p>

<p class='c032'><i>Distribution.</i>—The typical form is known from
Northern Venetia, Austria-Hungary (Styria, Carinthia,
Southern Tyrol, Carniola, Illyria, Istria, Croatia,
Slavonia, and eastward through Southern Hungary
to Transylvania), Dalmatia, Bosnia, Herzegovina,
Montenegro, Albania, and Servia. In the Alps up to
1,300 feet, in the Balkan Peninsula up to 7,500 feet.
The var. <i>montandoni</i> inhabits Roumania and Bulgaria.
<span class='pagenum'><a name='Page_256' id='Page_256'>256</a></span>
The var. <i>meridionalis</i> inhabits Greece, with the
Archipelago, Asia Minor, and Syria.</p>

<p class='c032'>The specimens from Transcaucasia constitute a
further variety (var. <i>transcaucasiana</i>, Boulenger),
agreeing with the var. <i>montandoni</i> in the rostral
scutellation and in the number of ventral shields
(150 to 156), but differing in the markings on the
back; these consist of dark bars or alternating
paired dark spots, as in the typical form of <i>V. aspis</i>.
The dark and light markings on the lower lip are
as in the typical <i>V. ammodytes</i>, and the lower surface
of the tail is pale yellow or greenish towards the
end.</p>

<p class='c032'><i>Habits.</i>—Notwithstanding its name <i>ammodytes</i>,
this Viper is by no means restricted to sandy
localities; on the contrary, it shows a predilection
for dry stony hills with low vegetation, and has
often been found climbing bushes. It avoids thick
forest, but occurs on the edges of woods and in
clearings, as well as on the borders of roads through
woods. In the cooler regions of the mountains,
which it ascends to a considerable altitude, it is
essentially diurnal, leaving its retreat only when
the sun shines; but in warm localities it is stated
to be principally nocturnal, appearing in numbers
by moonlight. The length of its period of hibernation
depends entirely on the climate, but when
the winter is mild it may be seen about in midwinter
whenever the sun shines. The poison of
<span class='pagenum'><a name='Page_257' id='Page_257'>257</a></span>
this Viper is stated to be more active than that
of <i>V. berus</i> and <i>V. aspis</i>, and, as the snake is very
common in some parts of Austria and the Balkan
Peninsula, fatal accidents to man are frequent.</p>

<p class='c032'>The food consists of small mammals and birds,
and also of lizards. <i>V. ammodytes</i> does much better
in captivity than its European congeners, and takes
food more readily.</p>

<p class='c032'>The hissing is louder than in <i>V. berus</i> and <i>V. aspis</i>,
and it is often produced, on the approach of man,
by specimens lying in such perfect concealment that
their presence would not otherwise be suspected;
this habit, like the rattling of the <i>Crotalus</i>, is evidently
detrimental to the species in its relation
to man.</p>

<p class='c032'>This species is extremely abundant in some parts
of Austria, and over 7,000 specimens were killed in
a district of Southern Styria in the course of two
years (1892, 1893). According to Werner, it is the
commonest of all snakes in Bosnia and Herzegovina.</p>

<p class='c032'><i>Reproduction.</i>—Pairing takes place in the spring,
sooner or later according to altitudes, and the young,
five to fourteen in number, are born in August.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    27. <span class='sc'>Vipera lebetina</span>, Linnæus<br />
    The Blunt-Nosed Viper, or Kufi
  </div>
</div>

<p class='c032'><i>Form.</i>—Short and heavy. Snout rounded, obtuse,
usually with well-marked canthus, and the loreal
region slanting towards the mouth. Eye small, its
<span class='pagenum'><a name='Page_258' id='Page_258'>258</a></span>
vertical diameter less than its distance from the
mouth in the adult. Nostril large and directed
backwards. Length of tail six (males) to ten times
(females) in the total length.</p>

<p><a id='f41' name='f41' href='#f41'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_299.jpg' width="200" height="128"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 41</span> (after Sordelli)</p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral as deep as broad, a little
broader than deep, or slightly deeper than broad,
reaching or nearly reaching the upper surface of
the snout, and in contact with two or three apical
shields. Upper surface of head covered with small
subimbricate
scales, which
are all more
or less distinctly
keeled,
or, rarely,
smooth on the
snout and
forehead;
seven to
twelve longitudinal series of scales between the
eyes (supraoculars included); two to four canthal
shields, of which the anterior is the largest, and
may be regarded as a supranasal. Supraocular
narrow, usually broken up into two or more small
shields. Twelve to eighteen scales round the eye;
two or three series of scales between the eye
and the labials; two or three vertical series of
scales separate the preoculars from the nasal,
which is single and often strongly hollowed out,
<span class='pagenum'><a name='Page_259' id='Page_259'>259</a></span>
and usually partially fused with the naso-rostral.
Upper labials nine to twelve, usually fourth and fifth
below the eye. Temporal scales keeled. Four or
five lower labials in contact with the single pair of
chin-shields.</p>

<p class='c032'><i>Scales</i> in twenty-three to twenty-seven rows,
usually twenty-five, with two apical pits, strongly
keeled, those of the outer row smooth or feebly keeled.
Ventral shields 151 to 177 in males, 153 to 180 in
females; anal entire; subcaudals 42 to 51 in males,
38 to 49 in females.</p>

<p class='c032'><i>Coloration.</i>—Very variable. The typical form,
which alone is represented in Europe, and was
originally described from Cyprus, is grey, greyish-buff,
or pale brown, above, with two dorsal series
of darker spots, which may stand in pairs, alternate,
or unite to form cross-bars, and a lateral series of
large dark spots or bars. A more or less distinct
dark band on each side of the head, passing through
the eye and often extending to the neck; a dark
bar or triangular spot below the eye, and usually
another below the nostril. Lower parts pinkish-white,
powdered with grey-brown, with or without
dark brown spots; end of tail yellow. The ground
colour of the young is pink or flesh-colour. In
specimens from desert sandy regions in Asia and
North Africa the markings may be very indistinct,
the snake being of a nearly uniform pale buff.</p>

<p class='c032'>In the var. <i>mauritanica</i>, Guichenot, from Morocco
<span class='pagenum'><a name='Page_260' id='Page_260'>260</a></span>
and Algeria, the back has three series of very large
dark brown or reddish-brown spots, separated by a
network of the yellowish ground colour, or the
middle series may be transformed into a wavy or
zigzag band. The scales in this variety are usually
in twenty-seven rows, instead of twenty-five (rarely
twenty-three) as in the typical form.</p>

<p class='c032'><i>Size.</i>—This species, the largest of European
Vipers, grows to a length of
4<span class='nom'>1</span>⁄<span class='dem'>2</span>
feet.</p>

<p class='c032'><i>Distribution.</i>—The European habitat of <i>V. lebetina</i>
is restricted to the Cyclades, where it is not uncommon
on the island of Tinos, and appears to be
found also on Kimoli. It is common on Cyprus,
where it is called <i>Kufi</i>, or Deaf Snake, and extends
from Syria and Asia Minor through Transcaucasia,
Mesopotamia, Persia, Northern Baluchistan, to
Afghanistan and Cashmere. It is further found on
the Atlas of Morocco and Algeria, near Oran and
Bona, and in Tunisia. Its reported occurrence in
Egypt has not been confirmed by recent investigations.</p>

<p class='c032'><i>Habits.</i>—According to M. Doumergue—who has
had ample opportunities of observing this Viper near
Oran, where it is common—it is a nocturnal reptile,
rarely moving about in the daytime. It inhabits
rocky localities, where there is brushwood, and
vineyards. During the day it remains sluggish
under large stones. It is most frequently met with
in April and May.</p>

<p class='c032'>
<span class='pagenum'><a name='Page_261' id='Page_261'>261</a></span>
On Milos, Dr. de Bedriaga observed this much-dreaded
snake, the bite of which is probably as bad
as that of its Indian ally, the Daboia, <i>V. russelli</i>, to
occur frequently in gardens, and to crawl about
near houses in villages after sunset. The same
observer has noted a sort of valvular closing of
the nostril through raising of the posterior part of
the nasal shield when the snake prepares to strike.</p>

<p class='c032'>The food consists principally of mammals up to
the size of a rabbit.</p>

<p class='c032'><i>Reproduction.</i>—According to Doumergue’s observations
in Algeria, the young, up to thirteen in
number, are born in May and June.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >
    <span class='sc'>Genus ANCISTRODON, Palisot de Beauvois</span>
  </div>
</div>

<p class='c032'>Head distinct from neck, its upper surface covered
with large shields, as in the normal <i>Colubridæ</i>; a
loreal pit; eye moderate or small, with vertical
pupil. Body moderately elongate or short. Scales
keeled (or smooth), with apical pits. Tail moderate
or short.</p>

<p class='c032'>This genus is distributed over nearly the whole
of Asia, the eastern parts of the United States of
America, and Mexico and Central America. One
of the Asiatic species just penetrates into South-Eastern
Europe, and is the sole representative of
the Crotalinæ in this part of the world.</p>

<div class='nf-center-c0'>
<div class='nf-center c039'  >

<span class='pagenum'><a name='Page_262' id='Page_262'>262</a></span>
28. <span class='sc'>Ancistrodon halys</span>, Pallas<br />
    Pallas’s Pit-Viper
  </div>
</div>

<p class='c032'><i>Form.</i>—Moderately elongate. Head subtriangular,
flat or slightly concave above, swollen in the temporal
region, very distinct from neck; snout rounded
or obtusely pointed, slightly turned up at the end,
with obtuse canthus and vertical or slightly oblique
loreal region; eye rather small. Tail seven to eight
and a half times in the total length.</p>

<p><a id='f42' name='f42' href='#f42'></a></p>
<div class='figcenter'>
  <img src='https://brian.carnell.com/wiki/_media/etext:g:ga-boulenger-snakes-of-europe-i_303.jpg' width="200" height="121"
    alt=""/>
<p class='caption'><span class='sc'>Fig. 42</span></p>
</div>

<p class='c032'><i>Head-Shields.</i>—Rostral as deep as broad or slightly
broader than deep, just visible from above. A pair
of internasals and a pair of larger prefrontals.
Frontal as broad as the supraocular, as long as or
a little longer than its distance from the end of the
snout, as long as or a little shorter than the rather
short parietals. Supraocular extending beyond the
vertical of the posterior border of the eye. Loreal
pit between three shields, separated from the labials.
Nostril between two nasals, the posterior of which
<span class='pagenum'><a name='Page_263' id='Page_263'>263</a></span>
is separated from the upper preocular by a loreal.
Two preoculars, one or two postoculars, and a subocular.
Three large lower temporals, anterior largest.
Upper labials seven or eight, third and fourth
largest, third entering the eye. A pair of small
chin-shields.</p>

<p class='c032'><i>Scales</i> sharply keeled, with two apical pits, in
twenty-three rows. Ventral shields 149 to 174; anal
entire; subcaudals 31 to 44 pairs.</p>

<p class='c032'><i>Coloration.</i>—Pale yellowish-grey, greyish-brown,
or reddish, sometimes greenish in young specimens,
with transverse series of darker spots or with more or
less regular dark bars with serrated edges across the
back (<a href='#p14'>Plate XIV</a>.); these bars may be narrower than
the interspaces between them, or so large as to cause
the back to appear brown with light cross-bars; the
bars sometimes broken up on the vertebral line, and
the two halves alternating. The sides usually paler
and bearing two alternating longitudinal series of
small spots, the lower of which are usually darker,
and sometimes extend on the outer ends of the
ventral shields. Head pale above, with a dark spot
on the middle of the snout, a cross-bar or a pair
of spots between the eyes, a spot or short band on
each side of the parietal region, and a horseshoe-shaped
band on the occiput, the branches of which are
more or less produced on the nape; all these markings
sometimes confluent. A broad, dark, light-edged
band on the temple. Lips whitish, speckled
<span class='pagenum'><a name='Page_264' id='Page_264'>264</a></span>
with brown. Lower parts whitish, more or less
profusely speckled with grey or brown. The horny
shield terminating the tail usually dark brown or
black at the end.</p>

<p class='c032'><i>Size.</i>—This species rarely reaches a length of
29 inches. The largest specimen in the British
Museum measures only 19 inches.</p>

<p class='c032'><i>Distribution.</i>—From the north and east coasts
of the Caspian Sea, across Central Asia to the
Upper Yenissei, as far north as 51°. In Europe it
is only known from two arid tracts between the
Volga and the Ural, near the Caspian Sea, viz., the
Saltan-Murat desert and the Induski hills.</p>

<p class='c032'><i>Habits.</i>—Nothing has been published on the
habits of this snake, but they are probably similar
to those of its near and more eastern relative,
<i>A. blomhoffi</i>, Schlegel, which inhabits China and
Japan. <i>A. blomhoffi</i> is said to be more or less
nocturnal, although showing a predilection for
localities well exposed to the sun. It is ovoviviparous.
The symptoms of its bite, which is
rarely fatal to man, are the same as in the Vipers.</p>

<p class='c032'>All the species of <i>Ancistrodon</i>, so far as they
have been observed, are in the habit of raising and
vibrating the tail, like the Rattlesnakes, when coiling
themselves up in a defensive attitude.</p>

<div class='chapter'>

<span class='pagenum'><a name='Page_265' id='Page_265'>265</a></span>
  <h2 id='in' class='c003'>INDEX</h2>
</div>
<table style="width:75%;" summary="alpha jump table">
	<tr>
		<td>  <a href="#IX_A">A</a></td>
		<td>  <a href="#IX_B">B</a></td>
		<td>  <a href="#IX_C">C</a></td>
		<td>  <a href="#IX_D">D</a></td>
		<td>  <a href="#IX_E">E</a></td>
		<td>  <a href="#IX_F">F</a></td>
		<td>  <a href="#IX_G">G</a></td>
		<td>  <a href="#IX_H">H</a></td>
		<td>  <a href="#IX_I">I</a></td>
		<td>  <a href="#IX_J">J</a></td>
		<td>  <a href="#IX_K">K</a></td>
		<td>  <a href="#IX_L">L</a></td>
		<td>  <a href="#IX_M">M</a></td>
	</tr>
	<tr>
		<td>  <a href="#IX_N">N</a></td>
		<td>  <a href="#IX_O">O</a></td>
		<td>  <a href="#IX_P">P</a></td>
		<td>  <a href="#IX_Q">Q</a></td>
		<td>  <a href="#IX_R">R</a></td>
		<td>  <a href="#IX_S">S</a></td>
		<td>  <a href="#IX_T">T</a></td>
		<td>  <a href="#IX_U">U</a></td>
		<td>  <a href="#IX_V">V</a></td>
		<td>  <a href="#IX_W">W</a></td>
		<td>  <a href="#IX_X">X</a></td>
		<td>  <a href="#IX_Z">Z</a></td>
             <td></td>
	</tr>
</table>
<p class='c042'><a id="IX_A"></a>
Acanthocephala, <a href='#Page_110'>110</a></p>

<p class='c043'><i>Acrochordinæ</i>, <a href='#Page_5'>5</a></p>

<p class='c043'>Adder, <a href='#Page_230'>230</a></p>

<p class='c043'>Æsculapian Snake, <a href='#Page_187'>187</a></p>

<p class='c043'><i>æsculapii</i> (<i>Coluber</i>), <a href='#Page_187'>187</a></p>

<p class='c043'><i>Aglypha</i>, <a href='#Page_4'>4</a>, <a href='#Page_151'>151</a></p>

<p class='c043'><i>Ailurophis vivax</i>, <a href='#Page_217'>217</a></p>

<p class='c043'>Albinism, <a href='#Page_39'>39</a></p>

<p class='c043'>Aldrovandi’s Snake, <a href='#Page_182'>182</a></p>

<p class='c043'>Altitudinal range, <a href='#Page_118'>118</a>, <a href='#Page_123'>123</a></p>

<p class='c043'><i>Amblycephalidæ</i>, <a href='#Page_5'>5</a></p>

<p class='c043'><i>ammodytes</i> (<i>Vipera</i>), <a href='#Page_249'>249</a></p>

<p class='c043'>Anal pockets, <a href='#Page_83'>83</a></p>

<p class='c043'>Anal shield, <a href='#Page_17'>17</a></p>

<p class='c043'><i>Ancistrodon</i>, <a href='#Page_261'>261</a></p>

<p class='c043'><i>Ancistrodon halys</i>, <a href='#Page_262'>262</a></p>

<p class='c043'>Antitoxic serums, <a href='#Page_66'>66</a></p>

<p class='c043'>Apical pits, <a href='#Page_15'>15</a>, <a href='#Page_75'>75</a></p>

<p class='c043'>Arteries, <a href='#Page_77'>77</a></p>

<p class='c043'>Ascariasis, <a href='#Page_111'>111</a></p>

<p class='c043'><i>asianus</i> (<i>Zamenis gemonensis</i>, var.), <a href='#Page_173'>173</a></p>

<p class='c043'>Asp Viper, <a href='#Page_239'>239</a></p>

<p class='c043'><i>aspis</i> (<i>Vipera</i>), <a href='#Page_239'>239</a></p>

<p class='c043'><i>astreptophorus</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_154'>154</a></p>

<p class='c043'><i>ater</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_156'>156</a></p>

<p class='c043'><i>atrovirens</i> (<i>Coluber</i>), <a href='#Page_170'>170</a></p>

<p class='c043'><i>aurolineatus</i> (<i>Coluber</i>), <a href='#Page_167'>167</a></p>

<p class='c043'><i>austriaca</i> (<i>Coronella</i>), <a href='#Page_197'>197</a></p>

<p class='c042'><a id="IX_B"></a>
Bacteria, <a href='#Page_113'>113</a></p>

<p class='c043'><i>berus</i> (<i>Pelias</i>), <a href='#Page_221'>221</a></p>

<p class='c043'><i>berus</i> (<i>Vipera</i>), <a href='#Page_230'>230</a></p>

<p class='c043'>Bezoar stones, <a href='#Page_141'>141</a></p>

<p class='c043'><i>bilineatus</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_154'>154</a></p>

<p class='c043'>Blind Snake, <a href='#Page_144'>144</a></p>

<p class='c043'>Blood-supply, <a href='#Page_77'>77</a></p>

<p class='c043'>Blunt-nosed Viper, <a href='#Page_257'>257</a></p>

<p class='c043'>Body, <a href='#Page_8'>8</a></p>

<p class='c043'><i>Boidæ</i>, <a href='#Page_4'>4</a>, <a href='#Page_146'>146</a></p>

<p class='c043'><i>Boinæ</i>, <a href='#Page_4'>4</a>, <a href='#Page_146'>146</a></p>

<p class='c043'><i>bosniensis</i> (<i>Vipera berus</i>, var.), <a href='#Page_236'>236</a></p>

<p class='c043'>Brain, <a href='#Page_73'>73</a></p>

<p class='c043'>Burrowing Snakes, <a href='#Page_91'>91</a></p>

<p class='c042'><a id="IX_C"></a></p>

<p class='c043'><i>cæruleus</i> (<i>Coluber</i>), <a href='#Page_233'>233</a></p>

<p class='c043'>Canker, <a href='#Page_113'>113</a></p>

<p class='c043'>Canthus rostralis, <a href='#Page_13'>13</a></p>

<p class='c043'>Captivity, <a href='#Page_100'>100</a></p>

<p class='c043'><i>carbonarius</i> (<i>Zamenis</i>), <a href='#Page_172'>172</a></p>

<p class='c043'><i>caspius</i> (<i>Zamenis gemonensis</i>, var.), <a href='#Page_172'>172</a></p>

<p class='c043'>Cat-Snake, <a href='#Page_217'>217</a></p>

<p class='c043'>Caucasian Cat-Snake, <a href='#Page_219'>219</a></p>

<p class='c043'><i>cervone</i> (<i>Elaphis</i>), <a href='#Page_182'>182</a></p>

<p class='c043'>Cestoda, <a href='#Page_112'>112</a></p>

<p class='c043'><i>cettii</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_155'>155</a></p>

<p class='c043'><i>chersoides</i> (<i>Tropidonotus</i>), <a href='#Page_167'>167</a></p>

<p class='c043'>Classification, <a href='#Page_2'>2</a></p>

<p class='c043'>Cobra di capello, <a href='#Page_9'>9</a></p>

<p class='c043'><i>Cœlopeltis</i>, <a href='#Page_207'>207</a></p>

<p class='c043'><i>Cœlopeltis monspessulana</i>, <a href='#Page_208'>208</a></p>

<p class='c043'><i>collaris</i> (<i>Contia</i>), <a href='#Page_207'>207</a></p>

<p class='c043'>Coloration, <a href='#Page_29'>29</a></p>

<p class='c043'>Colour, <a href='#Page_29'>29</a></p>

<p class='c043'><i>Coluber</i>, <a href='#Page_181'>181</a></p>

<p class='c043'><i>Coluber æsculapii</i>, <a href='#Page_187'>187</a></p>

<p class='c043'><i>Coluber atrovirens</i>, <a href='#Page_170'>170</a></p>

<p class='c043'><i>Coluber aurolineatus</i>, <a href='#Page_167'>167</a></p>

<p class='c043'><i>Coluber cæruleus</i>, <a href='#Page_233'>233</a></p>

<p class='c043'><i>Coluber dione</i>, <a href='#Page_185'>185</a></p>

<p class='c043'><i>Coluber dumfriesiensis</i>, <a href='#Page_200'>200</a></p>

<p class='c043'>
<span class='pagenum'><a name='Page_266' id='Page_266'>266</a></span>
<i>Coluber flavescens</i>, <a href='#Page_187'>187</a></p>

<p class='c043'><i>Coluber hydrus</i>, <a href='#Page_160'>160</a></p>

<p class='c043'><i>Coluber insignitus</i>, <a href='#Page_208'>208</a></p>

<p class='c043'><i>Coluber leopardinus</i>, <a href='#Page_191'>191</a></p>

<p class='c043'><i>Coluber longissimus</i>, <a href='#Page_187'>187</a></p>

<p class='c043'><i>Coluber quadrilineatus</i>, <a href='#Page_191'>191</a></p>

<p class='c043'><i>Coluber quatuorradiatus</i>, <a href='#Page_182'>182</a></p>

<p class='c043'><i>Coluber quatuorlineatus</i>, <a href='#Page_182'>182</a></p>

<p class='c043'><i>Coluber riccioli</i>, <a href='#Page_202'>202</a></p>

<p class='c043'><i>Coluber rubens</i>, <a href='#Page_204'>204</a></p>

<p class='c043'><i>Coluber sauromates</i>, <a href='#Page_183'>183</a></p>

<p class='c043'><i>Coluber scalaris</i>, <a href='#Page_194'>194</a></p>

<p class='c043'><i>Coluber torquatus</i>, <a href='#Page_152'>152</a></p>

<p class='c043'><i>Coluber viridiflavus</i>, <a href='#Page_170'>170</a></p>

<p class='c043'><i>Colubridæ</i>, <a href='#Page_4'>4</a>, <a href='#Page_150'>150</a></p>

<p class='c043'><i>Colubrinæ</i>, <a href='#Page_4'>4</a>, <a href='#Page_151'>151</a></p>

<p class='c043'><i>concolor</i> (<i>Tropidonotus tessellatus</i>, var.), <a href='#Page_162'>162</a></p>

<p class='c043'><i>concolor</i> (<i>Vipera berus</i>, var.), <a href='#Page_234'>234</a></p>

<p class='c043'><i>Coniophis</i>, <a href='#Page_7'>7</a></p>

<p class='c043'>Constriction, <a href='#Page_96'>96</a></p>

<p class='c043'><i>Contia</i>, <a href='#Page_205'>205</a></p>

<p class='c043'><i>Contia modesta</i>, <a href='#Page_205'>205</a></p>

<p class='c043'>Coral-Snakes, <a href='#Page_32'>32</a>, <a href='#Page_34'>34</a>, <a href='#Page_35'>35</a></p>

<p class='c043'><i>Coronella</i>, <a href='#Page_196'>196</a></p>

<p class='c043'><i>Coronella austriaca</i>, <a href='#Page_197'>197</a></p>

<p class='c043'><i>Coronella girondica</i>, <a href='#Page_202'>202</a></p>

<p class='c043'><i>Coronella italica</i>, <a href='#Page_197'>197</a></p>

<p class='c043'>Coryphodonts, <a href='#Page_58'>58</a></p>

<p class='c043'><i>Crotalinæ</i>, <a href='#Page_5'>5</a>, <a href='#Page_220'>220</a></p>

<p class='c043'>Crotalon, <a href='#Page_20'>20</a></p>

<p class='c043'><i>Crotalus</i>, <a href='#Page_21'>21</a></p>

<p class='c043'><i>cucullatus</i> (<i>Macroprotodon</i>), <a href='#Page_213'>213</a></p>

<p class='c042'><a id="IX_D"></a></p>

<p class='c043'>Dahl’s Whip-Snake, <a href='#Page_177'>177</a></p>

<p class='c043'><i>dahlii</i> (<i>Zamenis</i>), <a href='#Page_177'>177</a></p>

<p class='c043'><i>Dasypeltinæ</i>, <a href='#Page_5'>5</a></p>

<p class='c043'>Defecation, <a href='#Page_99'>99</a></p>

<p class='c043'>Definition, <a href='#Page_1'>1</a></p>

<p class='c043'>Deglutition, <a href='#Page_98'>98</a></p>

<p class='c043'>Dentition, <a href='#Page_53'>53</a></p>

<p class='c043'>Desert Snakes, <a href='#Page_36'>36</a></p>

<p class='c043'>Development, <a href='#Page_88'>88</a></p>

<p class='c043'>Diacranterians, <a href='#Page_58'>58</a></p>

<p class='c043'>Dicephalous young, <a href='#Page_89'>89</a></p>

<p class='c043'>Digestion, <a href='#Page_99'>99</a></p>

<p class='c043'><i>dione</i> (<i>Coluber</i>), <a href='#Page_185'>185</a></p>

<p class='c043'>Dione Snake, <a href='#Page_185'>185</a></p>

<p class='c043'><i>Dipsadomorphinæ</i>, <a href='#Page_5'>5</a>, <a href='#Page_151'>151</a></p>

<p class='c043'>Disgorging, <a href='#Page_99'>99</a></p>

<p class='c043'>Distribution, <a href='#Page_118'>118</a></p>

<p class='c043'><i>Dolichosauria</i>, <a href='#Page_1'>1</a></p>

<p class='c043'><i>dorsalis</i> (<i>Pelias</i>), <a href='#Page_234'>234</a></p>

<p class='c043'>Drinking, <a href='#Page_101'>101</a></p>

<p class='c043'><i>dumfriesiensis</i> (<i>Coluber</i>), <a href='#Page_200'>200</a></p>

<p class='c043'>Dwarf Snake, <a href='#Page_205'>205</a></p>

<p class='c042'><a id="IX_E"></a></p>

<p class='c043'>Economic value, <a href='#Page_138'>138</a></p>

<p class='c043'>Eggs, <a href='#Page_85'>85</a></p>

<p class='c043'>Egg-eating Snakes, <a href='#Page_53'>53</a>, <a href='#Page_80'>80</a></p>

<p class='c043'>Egg-tooth, <a href='#Page_89'>89</a></p>

<p class='c043'><i>Elachistodontinæ</i>, <a href='#Page_5'>5</a></p>

<p class='c043'><i>Elaphis cervone</i>, <a href='#Page_182'>182</a></p>

<p class='c043'><i>Elapinæ</i>, <a href='#Page_5'>5</a></p>

<p class='c043'><i>Elaps</i>, <a href='#Page_35'>35</a></p>

<p class='c043'><i>elsneri</i> (<i>Coluber leopardinus</i>, var.), <a href='#Page_193'>193</a></p>

<p class='c043'>Embryo, <a href='#Page_88'>88</a></p>

<p class='c043'>Epiglottis, <a href='#Page_79'>79</a></p>

<p class='c043'><i>Eryx</i>, <a href='#Page_147'>147</a></p>

<p class='c043'><i>Eryx jaculus</i>, <a href='#Page_147'>147</a></p>

<p class='c043'>European Whip-Snake, <a href='#Page_170'>170</a></p>

<p class='c043'>External characters, <a href='#Page_8'>8</a></p>

<p class='c043'>Exuviæ, <a href='#Page_20'>20</a></p>

<p class='c043'>Exuviation, <a href='#Page_105'>105</a></p>

<p class='c043'>Eyes, <a href='#Page_11'>11</a>, <a href='#Page_73'>73</a></p>

<p class='c042'><a id="IX_F"></a></p>

<p class='c043'>False Smooth Snake, <a href='#Page_213'>213</a></p>

<p class='c043'><i>fallax</i> (<i>Tarbophis</i>), <a href='#Page_217'>217</a></p>

<p class='c043'>Fangs, <a href='#Page_55'>55</a></p>

<p class='c043'>Fascination, <a href='#Page_104'>104</a></p>

<p class='c043'>Fat-bodies, <a href='#Page_81'>81</a></p>

<p class='c043'>Faunistic works, <a href='#Page_130'>130</a></p>

<p class='c043'>Feigning death, <a href='#Page_104'>104</a></p>

<p class='c043'><i>fitzingeri</i> (<i>Coronella</i>), <a href='#Page_197'>197</a></p>

<p class='c043'><i>flavescens</i> (<i>Coluber</i>), <a href='#Page_187'>187</a></p>

<p class='c043'><i>flavescens</i> (<i>Tropidonotus tessellatus</i>, var.), <a href='#Page_163'>163</a></p>

<p class='c043'>Flukes, <a href='#Page_112'>112</a></p>

<p class='c043'>Flying Snakes, <a href='#Page_94'>94</a></p>

<p class='c043'>Food, <a href='#Page_95'>95</a></p>

<p class='c043'>Form, <a href='#Page_8'>8</a></p>

<p class='c043'>Fossils, <a href='#Page_6'>6</a></p>

<p class='c042'><a id="IX_G"></a></p>

<p class='c043'>Gape, <a href='#Page_11'>11</a></p>

<p class='c043'>Gastrosteges, <a href='#Page_15'>15</a></p>

<p class='c043'><i>gemonensis</i> (<i>Zamenis</i>), <a href='#Page_170'>170</a></p>

<p class='c043'>Genital organs, <a href='#Page_82'>82</a></p>

<p class='c043'><i>girondica</i> (<i>Coronella</i>), <a href='#Page_202'>202</a></p>

<p class='c043'>
<span class='pagenum'><a name='Page_267' id='Page_267'>267</a></span>
<i>Glauconiidæ</i>, <a href='#Page_4'>4</a></p>

<p class='c043'>Glottis, <a href='#Page_79'>79</a></p>

<p class='c043'>Grass Snake, <a href='#Page_152'>152</a></p>

<p class='c043'>Greek Blind Snake, <a href='#Page_144'>144</a></p>

<p class='c043'>Ground Snakes, <a href='#Page_91'>91</a></p>

<p class='c042'><a id="IX_H"></a></p>

<p class='c043'>Habits, <a href='#Page_91'>91</a></p>

<p class='c043'>Hæmogregarines, <a href='#Page_112'>112</a></p>

<p class='c043'><i>hagenbecki</i> (<i>Tropidonotus tessellatus</i>, var.), <a href='#Page_162'>162</a></p>

<p class='c043'><i>halys</i> (<i>Ancistrodon</i>), <a href='#Page_261'>261</a></p>

<p class='c043'>Head, <a href='#Page_10'>10</a></p>

<p class='c043'>Head-shields, <a href='#Page_17'>17</a></p>

<p class='c043'>Hearing, <a href='#Page_74'>74</a></p>

<p class='c043'>Heart, <a href='#Page_77'>77</a></p>

<p class='c043'><i>Helagras</i>, <a href='#Page_7'>7</a></p>

<p class='c043'>Hemipenes, <a href='#Page_82'>82</a></p>

<p class='c043'>Hibernation, <a href='#Page_105'>105</a></p>

<p class='c043'>Hind limbs, <a href='#Page_10'>10</a></p>

<p class='c043'><i>hippocrepis</i> (<i>Zamenis</i>), <a href='#Page_179'>179</a></p>

<p class='c043'>Hissing, <a href='#Page_102'>102</a></p>

<p class='c043'><i>Homalopsinæ</i>, <a href='#Page_5'>5</a></p>

<p class='c043'>Hood, <a href='#Page_9'>9</a></p>

<p class='c043'>Horseshoe Whip-Snake, <a href='#Page_179'>179</a></p>

<p class='c043'><i>hugyi</i> (<i>Vipera aspis</i>, var.), <a href='#Page_244'>244</a></p>

<p class='c043'>Hybrids, <a href='#Page_90'>90</a></p>

<p class='c043'><i>Hydrophiinæ</i>, <a href='#Page_5'>5</a></p>

<p class='c043'><i>hydrus</i> (<i>Coluber</i>), <a href='#Page_160'>160</a></p>

<p class='c043'>Hyoid apparatus, <a href='#Page_42'>42</a></p>

<p class='c042'><a id="IX_I"></a></p>

<p class='c043'><i>iberus</i> (<i>Tarbophis</i>), <a href='#Page_219'>219</a></p>

<p class='c043'><i>Iguanognathus</i>, <a href='#Page_54'>54</a></p>

<p class='c043'><i>Ilysiidæ</i>, <a href='#Page_4'>4</a></p>

<p class='c043'>Immunity, <a href='#Page_66'>66</a>, <a href='#Page_71'>71</a></p>

<p class='c043'><i>incertus</i> (<i>Tropidonotus viperinus</i>, var.), <a href='#Page_167'>167</a></p>

<p class='c043'>Incubation, <a href='#Page_88'>88</a></p>

<p class='c043'>Intelligence, <a href='#Page_101'>101</a></p>

<p class='c043'><i>insignitus</i> (<i>Coluber</i>), <a href='#Page_208'>208</a></p>

<p class='c043'>Integument, <a href='#Page_8'>8</a></p>

<p class='c043'>Intestines, <a href='#Page_79'>79</a></p>

<p class='c043'>Iris, <a href='#Page_37'>37</a></p>

<p class='c043'>Isodonts, <a href='#Page_58'>58</a></p>

<p class='c043'><i>italica</i> (<i>Coronella</i>), <a href='#Page_197'>197</a></p>

<p class='c042'><a id="IX_J"></a></p>

<p class='c043'>Jacobson’s organ, <a href='#Page_73'>73</a></p>

<p class='c043'><i>jaculus</i> (<i>Eryx</i>), <a href='#Page_147'>147</a></p>

<p class='c043'>Javelin Sand-Boa, <a href='#Page_147'>147</a></p>

<p class='c042'><a id="IX_K"></a></p>

<p class='c043'>Key to the identification, <a href='#Page_22'>22</a></p>

<p class='c043'>Kidneys, <a href='#Page_80'>80</a></p>

<p class='c043'>Kufi, <a href='#Page_257'>257</a></p>

<p class='c042'><a id="IX_L"></a></p>

<p class='c043'>Labial pits, <a href='#Page_76'>76</a></p>

<p class='c043'><i>Lacertilia</i>, <a href='#Page_1'>1</a></p>

<p class='c043'><i>lacertina</i> (<i>Natrix</i>), <a href='#Page_208'>208</a></p>

<p class='c043'>Ladder Snake, <a href='#Page_194'>194</a></p>

<p class='c043'>Largest Snakes, <a href='#Page_21'>21</a></p>

<p class='c043'>Larynx, <a href='#Page_79'>79</a></p>

<p class='c043'>Lataste’s Viper, <a href='#Page_247'>247</a></p>

<p class='c043'><i>latastii</i> (<i>Vipera</i>), <a href='#Page_247'>247</a></p>

<p class='c043'><i>lebetina</i> (<i>Vipera</i>), <a href='#Page_257'>257</a></p>

<p class='c043'>Leopard Snake, <a href='#Page_191'>191</a></p>

<p class='c043'><i>leopardinus</i> (<i>Coluber</i>), <a href='#Page_191'>191</a></p>

<p class='c043'><i>lineaticollis</i> (<i>Tropidonotus tessellatus</i>, var.), <a href='#Page_162'>162</a></p>

<p class='c043'>Liver, <a href='#Page_81'>81</a></p>

<p class='c043'>Livery of the young, <a href='#Page_38'>38</a></p>

<p class='c043'>Locomotion, <a href='#Page_93'>93</a></p>

<p class='c043'>Long-nosed Viper, <a href='#Page_249'>249</a></p>

<p class='c043'><i>longissimus</i> (<i>Coluber</i>), <a href='#Page_187'>187</a></p>

<p class='c043'>Loreal pit, <a href='#Page_75'>75</a></p>

<p class='c043'>Loreal region, <a href='#Page_12'>12</a></p>

<p class='c043'>Lungs, <a href='#Page_78'>78</a></p>

<p class='c043'>Lycodonts, <a href='#Page_58'>58</a></p>

<p class='c043'>Lymph-hearts, <a href='#Page_78'>78</a></p>

<p class='c042'><a id="IX_M"></a></p>

<p class='c043'><i>Macroprotodon</i>, <a href='#Page_212'>212</a></p>

<p class='c043'><i>Macroprotodon cucullatus</i>, <a href='#Page_213'>213</a></p>

<p class='c043'><i>macrops</i> (<i>Vipera</i>), <a href='#Page_224'>224</a></p>

<p class='c043'>Marine Snakes, <a href='#Page_92'>92</a>, <a href='#Page_95'>95</a></p>

<p class='c043'>Markings, <a href='#Page_29'>29</a></p>

<p class='c043'><i>mauritanica</i> (<i>Vipera lebetina</i>, var.), <a href='#Page_259'>259</a></p>

<p class='c043'>Melanism, <a href='#Page_39'>39</a></p>

<p class='c043'>Mental groove, <a href='#Page_13'>13</a></p>

<p class='c043'><i>meridionalis</i> (<i>Vipera ammodytes</i>, var.), <a href='#Page_253'>253</a></p>

<p class='c043'>Mimicry, <a href='#Page_35'>35</a></p>

<p class='c043'><i>modesta</i> (<i>Contia</i>), <a href='#Page_205'>205</a></p>

<p class='c043'><i>monspessulana</i> (<i>Cœlopeltis</i>), <a href='#Page_208'>208</a></p>

<p class='c043'><i>montandoni</i> (<i>Vipera ammodytes</i>, var.), <a href='#Page_252'>252</a></p>

<p class='c043'>Montpellier Snake, <a href='#Page_208'>208</a></p>

<p class='c043'>Mortality from Snake-bite, <a href='#Page_133'>133</a></p>

<p class='c043'><i>Mosasauria</i>, <a href='#Page_1'>1</a></p>

<p class='c043'><i>murorum</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_154'>154</a></p>

<p class='c042'>
<span class='pagenum'><a name='Page_268' id='Page_268'>268</a></span>
<a id="IX_N"></a></p>

<p class='c043'><i>Natrix lacertina</i>, <a href='#Page_208'>208</a></p>

<p class='c043'><i>Natrix vulgaris</i>, <a href='#Page_152'>152</a></p>

<p class='c043'><i>natrix</i> (<i>Tropidonotus</i>), <a href='#Page_152'>152</a></p>

<p class='c043'>Neck, <a href='#Page_9'>9</a></p>

<p class='c043'>Nematoda, <a href='#Page_111'>111</a></p>

<p class='c043'><i>Nerodia</i>, <a href='#Page_152'>152</a></p>

<p class='c043'>Nervous system, <a href='#Page_73'>73</a></p>

<p class='c043'><i>neumayeri</i> (<i>Cœlopeltis monspessulana</i>, var.), <a href='#Page_210'>210</a></p>

<p class='c043'><i>niger</i> (<i>Coluber longissimus</i>, var.), <a href='#Page_188'>188</a></p>

<p class='c043'><i>nigrescens</i> (<i>Tropidonotus tessellatus</i>, var.), <a href='#Page_162'>162</a></p>

<p class='c043'>Nocturnal Snakes, <a href='#Page_93'>93</a></p>

<p class='c043'>Northern Viper, <a href='#Page_230'>230</a></p>

<p class='c043'>Nostrils, <a href='#Page_13'>13</a>, <a href='#Page_74'>74</a></p>

<p class='c042'><a id="IX_O"></a></p>

<p class='c043'>Œsophagus, <a href='#Page_79'>79</a></p>

<p class='c043'>Olfactory organ, <a href='#Page_73'>73</a></p>

<p class='c043'><i>Ophidia</i>, <a href='#Page_1'>1</a></p>

<p class='c043'><i>Opisthoglypha</i>, <a href='#Page_4'>4</a>, <a href='#Page_151'>151</a></p>

<p class='c043'>Organs of a sixth sense, <a href='#Page_75'>75</a></p>

<p class='c043'>Orsini’s Viper, <a href='#Page_221'>221</a></p>

<p class='c043'>Oviparous Snakes, <a href='#Page_86'>86</a></p>

<p class='c043'>Oviposition, <a href='#Page_85'>85</a></p>

<p class='c043'>Ovoviviparous Snakes, <a href='#Page_85'>85</a></p>

<p class='c042'><a id="IX_P"></a></p>

<p class='c043'>Pairing, <a href='#Page_84'>84</a></p>

<p class='c043'>Pallas’s Pit-Viper, <a href='#Page_262'>262</a></p>

<p class='c043'>Parasites, <a href='#Page_107'>107</a></p>

<p class='c043'><i>Pelias berus</i>, <a href='#Page_221'>221</a></p>

<p class='c043'><i>Pelias dorsalis</i>, <a href='#Page_234'>234</a></p>

<p class='c043'>Pelvic arch, <a href='#Page_52'>52</a></p>

<p class='c043'><i>persa</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_154'>154</a></p>

<p class='c043'><i>persicus</i> (<i>Zamenis gemonensis</i>, var.), <a href='#Page_172'>172</a></p>

<p class='c043'><i>picturatus</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_155'>155</a></p>

<p class='c043'>Pit-Vipers, <a href='#Page_75'>75</a>, <a href='#Page_262'>262</a></p>

<p class='c043'>Poison apparatus, <a href='#Page_62'>62</a></p>

<p class='c043'>Poison fangs, <a href='#Page_55'>55</a>, <a href='#Page_62'>62</a></p>

<p class='c043'>Poison glands, <a href='#Page_62'>62</a></p>

<p class='c043'>Poisons, <a href='#Page_66'>66</a></p>

<p class='c043'><i>prester</i> (<i>Vipera</i>), <a href='#Page_235'>235</a></p>

<p class='c043'><i>Proteroglypha</i>, <a href='#Page_4'>4</a>, <a href='#Page_151'>151</a></p>

<p class='c043'>Protozoa, <a href='#Page_112'>112</a></p>

<p class='c043'><i>pseudaspis</i> (<i>Vipera berus</i>, var.), <a href='#Page_236'>236</a></p>

<p class='c043'>Pupil, <a href='#Page_12'>12</a></p>

<p class='c043'><i>Pythoninæ</i>, <a href='#Page_4'>4</a></p>

<p class='c042'><a id="IX_Q"></a></p>

<p class='c043'><i>quadrilineatus</i> (<i>Coluber</i>), <a href='#Page_191'>191</a></p>

<p class='c043'><i>quatuorradiatus</i> (<i>Coluber</i>), <a href='#Page_182'>182</a></p>

<p class='c043'><i>quatuorlineatus</i> (<i>Coluber</i>), <a href='#Page_182'>182</a></p>

<p class='c042'><a id="IX_R"></a></p>

<p class='c043'>Rattle, <a href='#Page_20'>20</a></p>

<p class='c043'>Rattlesnakes, <a href='#Page_20'>20</a>, <a href='#Page_103'>103</a></p>

<p class='c043'>Rattling, <a href='#Page_103'>103</a></p>

<p class='c043'>Reflex movements, <a href='#Page_106'>106</a></p>

<p class='c043'>Relation to man, <a href='#Page_133'>133</a></p>

<p class='c043'>Renard’s Viper, <a href='#Page_227'>227</a></p>

<p class='c043'><i>renardi</i> (<i>Vipera</i>), <a href='#Page_227'>227</a></p>

<p class='c043'>Replacement teeth, <a href='#Page_55'>55</a></p>

<p class='c043'>Reproduction, <a href='#Page_82'>82</a></p>

<p class='c043'>Reptation, <a href='#Page_93'>93</a></p>

<p class='c043'><i>Reptilia</i>, <a href='#Page_1'>1</a></p>

<p class='c043'><i>Rhiptoglossa</i>, <a href='#Page_1'>1</a></p>

<p class='c043'><i>riccioli</i> (<i>Coluber</i>), <a href='#Page_202'>202</a></p>

<p class='c043'>Ring-Snake, <a href='#Page_152'>152</a></p>

<p class='c043'><i>romanus</i> (<i>Coluber longissimus</i>, var.), <a href='#Page_188'>188</a></p>

<p class='c043'><i>rubens</i> (<i>Coluber</i>), <a href='#Page_204'>204</a></p>

<p class='c043'><i>rubro-maculosus</i> (<i>Tropidonotus tessellatus</i>, var.), <a href='#Page_162'>162</a></p>

<p class='c043'>Rustling, <a href='#Page_102'>102</a></p>

<p class='c042'><a id="IX_S"></a></p>

<p class='c043'>Sand-Boa, <a href='#Page_147'>147</a></p>

<p class='c043'>Sand-Snakes, <a href='#Page_91'>91</a></p>

<p class='c043'>Sand-Viper, <a href='#Page_249'>249</a></p>

<p class='c043'><i>sardus</i> (<i>Zamenis</i>), <a href='#Page_172'>172</a></p>

<p class='c043'><i>sauromates</i> (<i>Coluber</i>), <a href='#Page_183'>183</a></p>

<p class='c043'><i>scalaris</i> (<i>Coluber</i>), <a href='#Page_194'>194</a></p>

<p class='c043'><i>scalaris</i> (<i>Coronella austriaca</i>, var.), <a href='#Page_199'>199</a></p>

<p class='c043'>Scales, <a href='#Page_14'>14</a></p>

<p class='c043'><i>schwoederi</i> (<i>Coluber leopardinus</i>, var.), <a href='#Page_193'>193</a></p>

<p class='c043'><i>scutatus</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_155'>155</a></p>

<p class='c043'><i>semimaculata</i> (<i>Contia modesta</i>, var.), <a href='#Page_207'>207</a></p>

<p class='c043'>Sense organs, <a href='#Page_73'>73</a></p>

<p class='c043'><i>seoanei</i> (<i>Vipera berus</i>, var.), <a href='#Page_235'>235</a></p>

<p class='c043'>Serotherapy, <a href='#Page_66'>66</a>, <a href='#Page_134'>134</a></p>

<p class='c043'>Serum treatment, <a href='#Page_67'>67</a></p>

<p class='c043'>Shedding of the epidermis, <a href='#Page_20'>20</a></p>

<p class='c043'>Shields, <a href='#Page_14'>14</a></p>

<p class='c043'>
<span class='pagenum'><a name='Page_269' id='Page_269'>269</a></span>
Sixth sense, <a href='#Page_75'>75</a></p>

<p class='c043'>Skeleton, <a href='#Page_40'>40</a></p>

<p class='c043'>Skull, <a href='#Page_40'>40</a></p>

<p class='c043'>Smallest Snakes, <a href='#Page_21'>21</a></p>

<p class='c043'>Smooth Snake, <a href='#Page_197'>197</a></p>

<p class='c043'>Snake-charmers, <a href='#Page_139'>139</a></p>

<p class='c043'>Snake-stones, <a href='#Page_141'>141</a></p>

<p class='c043'>Snake swallowing her young, <a href='#Page_88'>88</a></p>

<p class='c043'>Snake-worship, <a href='#Page_139'>139</a></p>

<p class='c043'>Snout, <a href='#Page_12'>12</a></p>

<p class='c043'>Solenoglyphs, <a href='#Page_56'>56</a></p>

<p class='c043'>Southern Smooth Snake, <a href='#Page_202'>202</a></p>

<p class='c043'><i>Squamata</i>, <a href='#Page_1'>1</a></p>

<p class='c043'><i>steindachneri</i> (<i>Vipera ammodytes</i>, var.), <a href='#Page_252'>252</a></p>

<p class='c043'>Stomach, <a href='#Page_79'>79</a></p>

<p class='c043'>Subcaudal shields, <a href='#Page_15'>15</a></p>

<p class='c043'><i>subfasciatus</i> (<i>Tropidonotus natrix</i>, var.), <a href='#Page_155'>155</a></p>

<p class='c043'><i>subgriseus</i> (<i>Coluber longissimus</i>, var.), <a href='#Page_189'>189</a></p>

<p class='c043'><i>Symoliophis</i>, <a href='#Page_7'>7</a></p>

<p class='c043'>Syncranterians, <a href='#Page_58'>58</a></p>

<p class='c042'><a id="IX_T"></a></p>

<p class='c043'>Tail, <a href='#Page_9'>9</a></p>

<p class='c043'><i>Tarbophis</i>, <a href='#Page_216'>216</a></p>

<p class='c043'><i>Tarbophis fallax</i>, <a href='#Page_217'>217</a></p>

<p class='c043'><i>Tarbophis iberus</i>, <a href='#Page_219'>219</a></p>

<p class='c043'>Teeth, <a href='#Page_53'>53</a></p>

<p class='c043'>Tessellated Water-Snake, <a href='#Page_160'>160</a></p>

<p class='c043'><i>tessellatus</i> (<i>Tropidonotus</i>), <a href='#Page_160'>160</a></p>

<p class='c043'>Thymus gland, <a href='#Page_78'>78</a></p>

<p class='c043'>Ticks, <a href='#Page_108'>108</a></p>

<p class='c043'>Tongue, <a href='#Page_74'>74</a></p>

<p class='c043'>Tongue-worms, <a href='#Page_108'>108</a></p>

<p class='c043'><i>torquatus</i> (<i>Coluber</i>), <a href='#Page_152'>152</a></p>

<p class='c043'><i>trabalis</i> (<i>Zamenis gemonensis</i>, var.), <a href='#Page_172'>172</a></p>

<p class='c043'>Trachea, <a href='#Page_78'>78</a></p>

<p class='c043'><i>transcaucasiana</i> (<i>Vipera ammodytes</i>, var.), <a href='#Page_256'>256</a></p>

<p class='c043'>Tree-Snakes, <a href='#Page_36'>36</a>, <a href='#Page_92'>92</a>, <a href='#Page_94'>94</a></p>

<p class='c043'>Trematoda, <a href='#Page_112'>112</a></p>

<p class='c043'><i>Tropidonotus</i>, <a href='#Page_152'>152</a></p>

<p class='c043'><i>Tropidonotus chersoides</i>, <a href='#Page_167'>167</a></p>

<p class='c043'><i>Tropidonotus natrix</i>, <a href='#Page_152'>152</a></p>

<p class='c043'><i>Tropidonotus tessellatus</i>, <a href='#Page_160'>160</a></p>

<p class='c043'><i>Tropidonotus viperinus</i>, <a href='#Page_165'>165</a></p>

<p class='c043'><i>Typhlopidæ</i>, <a href='#Page_4'>4</a>, <a href='#Page_143'>143</a></p>

<p class='c043'><i>Typhlops</i>, <a href='#Page_144'>144</a></p>

<p class='c043'><i>Typhlops vermicularis</i>, <a href='#Page_144'>144</a></p>

<p class='c042'><a id="IX_U"></a></p>

<p class='c043'>Ureters, <a href='#Page_81'>81</a></p>

<p class='c043'><i>Uropeltidæ</i>, <a href='#Page_5'>5</a></p>

<p class='c043'>Urosteges, <a href='#Page_15'>15</a></p>

<p class='c043'><i>ursinii</i> (<i>Vipera</i>), <a href='#Page_221'>221</a></p>

<p class='c042'><a id="IX_V"></a></p>

<p class='c043'>Veins, <a href='#Page_77'>77</a></p>

<p class='c043'><i>veithi</i> (<i>Coronella austriaca</i>, var.), <a href='#Page_199'>199</a></p>

<p class='c043'>Ventral shields, <a href='#Page_15'>15</a></p>

<p class='c043'><i>vermicularis</i> (<i>Typhlops</i>), <a href='#Page_144'>144</a></p>

<p class='c043'>Vertebræ, <a href='#Page_50'>50</a></p>

<p class='c043'>Vertebral column, <a href='#Page_50'>50</a></p>

<p class='c043'><i>Vipera</i>, <a href='#Page_221'>221</a></p>

<p class='c043'><i>Vipera ammodytes</i>, <a href='#Page_249'>249</a></p>

<p class='c043'><i>Vipera aspis</i>, <a href='#Page_239'>239</a></p>

<p class='c043'><i>Vipera berus</i>, <a href='#Page_230'>230</a></p>

<p class='c043'><i>Vipera latastii</i>, <a href='#Page_247'>247</a></p>

<p class='c043'><i>Vipera lebetina</i>, <a href='#Page_257'>257</a></p>

<p class='c043'><i>Vipera macrops</i>, <a href='#Page_224'>224</a></p>

<p class='c043'><i>Vipera prester</i>, <a href='#Page_235'>235</a></p>

<p class='c043'><i>Vipera renardi</i>, <a href='#Page_227'>227</a></p>

<p class='c043'><i>Vipera ursinii</i>, <a href='#Page_221'>221</a></p>

<p class='c043'><i>Viperidæ</i>, <a href='#Page_5'>5</a>, <a href='#Page_220'>220</a></p>

<p class='c043'><i>Viperinæ</i>, <a href='#Page_5'>5</a>, <a href='#Page_220'>220</a></p>

<p class='c043'>Viperine Water-Snake, <a href='#Page_165'>165</a></p>

<p class='c043'><i>viperinus</i> (<i>Tropidonotus</i>), <a href='#Page_165'>165</a></p>

<p class='c043'><i>viridiflavus</i> (<i>Coluber</i>), <a href='#Page_170'>170</a></p>

<p class='c043'>Viscera, <a href='#Page_77'>77</a></p>

<p class='c043'><i>vivax</i> (<i>Ailurophis</i>), <a href='#Page_217'>217</a></p>

<p class='c043'><i>vosseleri</i> (<i>Tropidonotus tessellatus</i>, var.), <a href='#Page_162'>162</a></p>

<p class='c043'><i>vulgaris</i> (<i>Natrix</i>), <a href='#Page_152'>152</a></p>

<p class='c042'><a id="IX_W"></a></p>

<p class='c043'>Warning coloration, <a href='#Page_35'>35</a>, <a href='#Page_36'>36</a></p>

<p class='c043'>Water-Snakes, <a href='#Page_92'>92</a>, <a href='#Page_94'>94</a>, <a href='#Page_160'>160</a></p>

<p class='c043'>Whip-Snake, <a href='#Page_170'>170</a></p>

<p class='c043'>Worms, <a href='#Page_110'>110</a></p>

<p class='c042'><a id="IX_X"></a></p>

<p class='c043'><i>Xenopeltidæ</i>, <a href='#Page_5'>5</a></p>

<p class='c042'><a id="IX_Z"></a></p>

<p class='c043'><i>Zamenis</i>, <a href='#Page_170'>170</a></p>

<p class='c043'><i>Zamenis carbonarius</i>, <a href='#Page_172'>172</a></p>

<p class='c043'><i>Zamenis dahlii</i>, <a href='#Page_177'>177</a></p>

<p class='c043'><i>Zamenis gemonensis</i>, <a href='#Page_170'>170</a></p>

<p class='c043'><i>Zamenis hippocrepis</i>, <a href='#Page_179'>179</a></p>

<p class='c043'><i>Zamenis sardus</i>, <a href='#Page_172'>172</a></p>

<p class='c043'>Zoogeographical Regions, <a href='#Page_119'>119</a></p>

<div class='pbb'></div>
<hr class='pb' />

<div class='nf-center-c0'>
<div class='nf-center c024'  >
    PRINTED BY<br />
    BILLING AND SONS, LTD.,<br />
    GUILDFORD
  </div>
</div>

<div class='pbb'></div>
<hr class='pb' />
<hr class='c044' />
<table class='fntab' summary='footnote_1'>
<tr><td class='c045'>
<div id='f1'><a href='#r1' class='c038'>[1]</a></div>
</td><td>
<div class='footnote'>
<p class='c032'>For a key to the identification of the species, see above, p. <a href='#Page_22'>22</a>.</p>
</div>
</td></tr>
</table>

<table class='fntab' summary='footnote_2'>
<tr><td class='c045'>
<div id='f2'><a href='#r2' class='c038'>[2]</a></div>
</td><td>
<div class='footnote'>
<p class='c032'>The only specimen with twenty-one rows I have examined
is a male from Albano, near Rome (Genoa Museum).</p>
</div>
</td></tr>
</table>
</html>