UNIVERSITY 



OF 



THE REPTILES 193 



adapt themselves to their new surroundings, become tame, 

 and feast on flies, ants, and other insects, which they cap- 

 ture by the aid of their long tongue. The horned toads 

 are perfectly harmless creatures, but when irritated some- 

 times perform the remarkable feat of spurting a stream of 

 blood from the eye toward the intruding object for a dis- 

 tance of several inches. This has been regarded by some 

 as a zoological fable ; but there are many who have watched 

 the horned toad in its natural state and in captivity, and 

 they assure us that it is a fact. 



In the hot deserts of Arizona and Sonora is another 

 peculiar species of lizard known as the Gila monster (Hclo- 

 derma) (Fig. 115), having the distinction of being the only 

 poisonous lizard known. Further protection is afforded 

 by bony tubercles on the head and by scales over the 

 remainder of the body, all of which are colored brown or 

 various shades of yellow, giving the animal a peculiar 

 streaked and blotched appearance. 



182. Distribution of the snakes. The snakes are much 

 more common than the lizards. All over the United States 

 one meets with them, especially the garter- or water-snakes. 

 Of less wide distribution are the black-, grass-, and milk- 

 snakes, and a number of less known species, all of which 

 are perfectly harmless and often make interesting pets. 

 Some of them when cornered show considerable temper, 

 flatten the head and hiss violently, and imitate poisonous 

 forms, but venomous snakes are comparatively few in num- 

 ber in northern and eastern United States. In the south- 

 ern portions of the country they become more abundant. 

 Along the streams and in the swamps the copperheads, and 

 especially the water-moccasins, often lie in wait for frogs 

 and fish. Both these species are especially dreaded, as they 

 strike without giving any warning sound, but the name 

 and bad reputation of the moccasin is often, especially in 

 the South, transferred to perfectly harmless water-snakes. 

 On higher ground are the rattlesnakes (Crotalus), once 



