334! CLASS REPTILIA. 



ponds and streams. They also climb up trees with remark- 

 able agility, to surprise and devour the young birds. 



They lay from jfifteen to forty eggs in holes on the edge 

 of waters, in dunghills, and in hay-cocks. They are oval, 

 as large as one"'s finger, and attached together in chaplets. 

 They disclose the young about the middle of summer, and 

 before winter the young are already six inches long. The 

 length of the adult is three feet and a half ; there are eight 

 or nine varieties. 



We insert a plate of the exuvia of this species. Fig. 1, 

 represents the dorsal squamae ; 2, the abdominal scutor and 

 squamae ; 3, the cellular substance ; and 4, the fibrous tex- 

 ture of the scales— the last two greatly magnified. This 

 cellular and fibrous construction which prevails throughout 

 the skin, as well in the scuta as in the squamae, seems ne- 

 cessary to the extraordinary power of dilatation which the 

 ophidians possess in swallowing their food. 



The Colatrovirens, Lac, which is called by Shaw the 

 French snake, is the handsomest of the European species. 

 Its size varies from three to four feet, and sometimes it is 

 even five feet long. Its circumference is about three inches 

 at most in the thickest part. 



This reptile is not uncommon in the southern provinces 

 of France, in the Bordelais, Poitou, &c. ; it is sometimes 

 found even as far as Fontainbleau. It usually fixes its habi- 

 tation in woods, along hedges, or even in the midst of rocks 

 or heaps of stones ; it generally feeds on birds, mice, frogs, 

 toads, &c. ; it climbs trees and swims well. Daubenton was 

 the first writer who has spoken of it ; but the name of 

 common adder {couleuvre commune) which he has given to 

 it, is much more suitable to the colubur natrioo. 



M. Bosc tells us, that at the end of summer, some time 

 before they conceal themselves, these adders are heard to hiss 



