134 



MAN, — THE ANIMAL 



duction of poison. The duct (Fig. 44) from this 

 gland opens into the base of a hollow tooth. 

 When the rattlesnake strikes its victim, the jaws 

 are thrown back and the whole head moves for- 

 ward toward its victim. The teeth on the upper 

 jaw penetrate the skin. As the head is with- 

 drawn, the muscles over the body of the gland 



Figure 44. Diagram of the head of a rattlesnake. The skin 

 and part of the muscles have been .removed. The long oval 

 mass in the upper jaw which is connected by a tube with the 

 curved tooth, the poison fang, is the poison sac or gland. This 

 is a modified salivary gland. There is an oval pit just below 

 the round nostril opening which is present in poisonous snakes 

 only. 



press on the gland and thus help to force the 

 poison into the victim. 



The following shows what actually happens 

 after this poison enters the blood of man: One 

 of the attendants at the National Zoological Park 

 was bitten, on August 17, on the middle finger of 

 the left hand. The wound was immediately 

 sucked and within fifteen minutes cauterized with 

 a I per cent, solution of potassium permanganate. 



