370 



LOWER VERTEBRATES. 



seized, without first waiting for it to die. This haliit lias often resulted in considerable 

 interest to those uufaiiiiliar with it. Not infreq\iently the snake can be induced, on 

 in-itation, to disgorge a well-secured meal, wliich often apjiears as a lively froL?, that 

 hops away with all the experience, if without the understanding, of Jonah. The habit 

 may also explain tlie almost imiversal belief, of which more has been said in the intro- 

 duction, that certain snakes swallow their young in time of danger. Since a serpent, 

 that had been made a meal of would live for some little time after being swallowed, 

 and if, in the meantime, the feasting snake were killed, the imjjrisoned animal would, if 

 liberated, crawl away with all the experience of the frog. 



We will first treat one of the largest genera, and the one that is the most typical 

 of the family ; its members are recognized by their keeled scales, regular arrangement 

 of the cervical plates, and by the numerous teeth of the jaws and palate, of which the 



Fig. 21G. — Tiophlnnolus natrix; • common suaUu ' ui Europe. 



anterior are shortest. The Tropidonoti are found in the neighborhood of water, as a 

 general rule, and, though not aquatic, are excellent swimmers, and, on being surprised, 

 will often choose this means of escape. Members of the genus are abundant in Xoi-th 

 America, Europe, Asia, and a portion of Australia, as well as some of the islands of the 

 Ea.stern Archipelago, though rare in Africa and South America. 



The illustration which has been selected to re])resent this large genus is th.at of 

 TrojJidonotus natrix, a form which is abundant throughout Europe, being particularly 

 fond of the neighborhood of ponds and streams, into which it often voluntarily plunges, 

 sometimes coiling itself up and remaining at the bottom for hours at a time. With 

 the common people it is known as the ringed or grass-snake, and is often tamed, soon 

 learning to distinguish its friends. In confinement it will eat beetles, grasshoppers, 

 frogs, and even ])read and milk. Of the dozen or more American representatives of this 

 genus, Troindonotus sipedon is, perhaps, the most familiar. This snake is found in 



