REPTILES 259 



The tongue, an organ of touch and taste, is very long and forked 

 at the end. The food is swallowed whole, and pushed down by 

 rhythmic contractions of the muscles surrounding the gullet. 

 Snakes usually refuse other than living prey. 



Alligators and crocodiles. Crocodiles are mostly confined to 

 Asia and Africa, while alligators are natives of North and South 

 America. The chief structural difference between them is that 

 the teeth in alligators are set in long sockets, while those of the 

 crocodiles are not. Both of these lizardlike animals have broad, 

 vertically flattened tails adapted to swimming. Their skins are 

 very tough and are covered with bony scales. 



Amer. Mus. of Nat. Hist. 

 Why is the alligator classified as a reptile ? 



Practical Exercise 17. Give a good definition of a reptile. What reptiles 

 are common in your locality ? 



Practical Exercise 18. What is one character by which you can distinguish 

 a reptile from an amphibian ? In what part of this country are reptiles most 

 numerous ? Why ? 



Reptiles. These animals are characterized by having scales 

 developed from the skin. In the turtle they have become bony 

 and are connected with the internal skeleton. Reptiles always 

 breathe by means of lungs, differing in this respect from the 

 amphibians and fishes. They have the same temperature as their 

 surroundings and usually hibernate as soon as winter comes. 

 They show their relationship to birds by laying large eggs, 

 incased in a leathery, limy shell. There are about 1500 known 

 species. 



