SNAKES. 33 



by ligaments. This enables them to open the mouth 

 very widely and to swallow animals much larger in 

 diameter than themselves. They swallow all food 

 whole without mastication. In this they are aided 

 by a copious flow of saliva which lubricates their 

 prey, and causes it to pass into the stomach more 

 readily. Whenever they catch a frog or other animal 

 with limbs they manipulate it in such a manner as to 

 enable them to swallow it head first. The limbs of 

 the victim are thus pressed close to its body and the 

 act of swallowing is but little hindered by their 

 presence. 



Snakes are "coldblooded" animals; i. e., their 

 bodily temperature is not constant like that of man, 

 but varies with the temperature of the air which they 

 breathe. On that account they become sluggish in 

 late autumn, and, seeking a crevice in a rock or hole 

 in the ground, they crawl into it and remain through- 

 out the winter, eating nothi ng and moving not. Large 

 numbers sometimes find their way to the same place 



and are often found coiled and twisted 

 Hibernation ,, xl ... . 



of Snakes together, thus giving rise to the many 



stories of so-called "snake dens." If 

 the winter be an open one this hibernation, as it is 

 called, is often interrupted and the animal comes forth 

 from its retreat on some warm sunny day, thinking, 

 no doubt, that spring has come again. During an 

 excessive thaw the high water often finds its way into 

 the snake's resting place and many are doubtless 

 drowned while still torpid. Others escape and make 

 their way to a higher and drier spot. Thus on Jan- 

 uary 11, 1890, the writer found two species of garter 



3 



