30 SiVAKES. 



if by suction. Now its legs are passive ; they no longer 

 kick right and left, but lie parallel, as by degrees they also 

 vanish, and only the four feet remain in sight. These 

 presently have been sucked in, and the skin of the snake is 

 stretched like a knitted stocking over the lump which tells 

 us just how far down Coluber's neck the frog has reached. 

 Gradually the lump gets farther and farther down, but is 

 less evident as it reaches the larger part of the body. The 

 snake remains still for a few moments till his jaws are 

 comfortably in place again ; then he yawns once or twice, 

 and finally retires for his siesta, and we to the bookshelves. 



* Snakes work their prey down through the collapsed 

 pharynx,' says Giinther. That is, the muscles of the throat 

 seize upon what is presented to them, and do their part, as 

 in other animals. Only, in most other animals there is the 

 action of swallowing, one mouthful at a time ; whereas in 

 serpents the action is continuous, the throat going on with 

 the work begun by the teeth, which in a snake is only 

 grasping and working the food in with a motion so gradual 

 as to simulate suction. The reason why the head and jaws 

 have been so enormously stretched and distorted, is because 

 all the bones are, in common language, loose ; that is, they 

 are not consolidated like the head-bones of higher animals, 

 but united by ligaments so elastic as to enable them to 

 separate in the way we have seen. This extends to the 

 jaws, and even to the palate, which is also armed with teeth, 

 two rows extending backwards. The lower jaw or mandible 

 being extremely long, the elastic ligament by which the 

 pair of bones is connected in front, forming the chin, enables 

 them to separate widely and move independently. This is 



