56 MANUAL OF NATURE STUDY. 



I 



What sort of tongue has the snake? Why does 

 he almost constantly keep darting it out of his 

 mouth? Examine the frog's tongue. Why is it 

 long and sticky? How does it catch its food? 

 Would a fleshy, sticky tongue be of any use to a 

 snake ? Explain that the snake does not seek for 

 gnats and flies as a frog does, but for much larger 

 animals, such as grasshoppers, frogs, birds and 

 mice, and that to hold such animals, a sticky tongue 

 would be of no particular use. A frog sits nearly 

 still upon its feet, slightly throwing its body and 

 head forward as it thrusts out its long, sticky tongue 

 to capture a fly or gnat that happens to draw too 

 near. The snake, with mouth wide open, throws 

 the front part of its body forward, and between its 

 wide open jaws, siezes its prey. The lower jaw is 

 composed of two parts, separated longitudinally, 

 each part moving forward and backward freely upon 

 the other. The upper jaw is provided with teeth 

 that point backward toward the throat ; also each 

 half of the lower jaw is so provided. Then in 

 swallowing food, the prey, while still alive, is held 

 firmly between the upper jaw and one half of the 

 lower jaw. The other half of the lower jaw is 

 thrust forward for a new hold. The process of 

 swallowing has been compared to a boy in a fixed 

 position pulling a load towards him by means of a 



