THE REPTILES 



277 



strychnine, which with the anti- venom serum, now easily obtained, 

 constitute almost sure protection. 



POISON APPARATUS OP i/VAKE. 



After Linville and Kelly, by permission ofGinn and Co. 



FIG. 94. Poison Apparatus of Snake. 



Fig. 1 shows the structure of the skull. Note the two hinges which permit 

 a forward and backward motion of the quadrate bone. This allows the lower 

 jaw to be extended and drawn back to aid in swallowing the prey. 



The very loose attachment of all the skull bones permits great freedom of 

 motion, needed when swallowing a victim larger than itself. 



The fangs are grooved or hollow, forming an outlet for the poisonous venom. 



Fig. 2 shows part of the head dissected away to expose the poison gland and 

 the muscles that press upon it when the snake strikes. The act of striking 

 forces the venom out through the fangs, into the wound. 



Fig. 3 is a diagram showing the poison gland, duct and fang removed. Also 

 the secondary fangs which develop to replace the large ones, if they are in- 

 jured or torn out in striking. 



