132 REPTILES 



young. Since snakes eat insects, frogs, mice, rats, and 

 rabbits, they should be considered beneficial. 



Rattlesnakes 1 and copperheads are the most common 

 poisonous snakes of our country. Their jaws are provided 

 with fangs (Figure 129), by means of which a poison 

 is injected into their prey. Large snakes like the black 

 snake or blue racer of the United States, the boa con- 



Figure 131. — Rattlesnake — -Poisonous. 

 Compare head with snake in Figure 132. 



strictor of South America, and the python (pi'thon) of 

 Asia are constrictors. They are able to wind their bodies 

 around their prey and to crush it to death. The most 

 deadly snake in the world is the cobra (ko'bra) of India, 

 where thousands of the natives die annually from the bite 

 of this snake. 



Snakes swallow their food whole, and as the teeth are 

 used merely for holding their prey, they point backwards. 



1 The two most common rattlesnakes are the mountain rattler and the 

 massasauge (mas-sa-sa'ge). 



