NATURE OF SNAKE VENOM. 357 
The majority of snake venoms contain all three of the above- 
The rat 
It drove its fangs home, paused for an instant and withdrew. 
tottered a few feet and died. 
140.—A male Puff Adder in the act of biting a rat. 
Fic. 
mentioned poisons. In each species of snake they are not only 
different more or less in their physiological action, but they are 
