2O2 ] Snakes and Frogs and Their Relatives 



It is not quite so simple as that. The snake has its poison supply 

 in two sacs one in either cheek. Each sac is connected to the 

 fangs by a duct that runs under the eye and over the bone to 

 which the fangs are attached. When the viper strikes, muscles 

 that surround the poison sacs, contract and force the venom 

 through the ducts into the fangs, from which it flows to the 

 wound just made in the victim's flesh. 



HEARTY EATERS 



The ability of snakes to swallow objects larger than them- 

 selves is one of their most spectacular traits. The larger snakes, 

 such as pythons or boas, sometimes devour a goat or small deer 

 whole. Such a feat would be impossible without a number of 

 special body features with which nature has provided them. 



Let's look at their jaws, for example. An extra bone hinges 

 the upper jaw to the lower, allowing them to spread far apart. 

 Also, the lower jawbones are held together only by elastic liga- 

 ments and they can separate at the chin to further increase the 

 size of the mouth. The teeth point backward and thus present 

 no obstacle to objects taken into the mouth. Even the snake's sides 

 are adapted to the task they have great elasticity and can stretch 

 to many times their normal dimensions! 



THE MOVABLE WINDPIPE 



Despite all these helps, you might still expect a snake to 

 choke to death swallowing anything large enough to force its 

 jawbones wide apart. The snake overcomes this difficulty by being 

 able to extend a portion of its windpipe forward even a few 

 inches beyond its open mouth if need be! By this means it can 

 breathe during the long slow process of forcing down a meal 

 apparently far too big for its size. 



Some species of snakes can live on three or four big meals a 

 year; others may eat a moderate meal every week or ten days. 



The Ways of a Rattler 



Children are understandably curious about the hows and whys 

 of a rattler's rattle. How does a tail tip turn into a rattle? Why 

 do some snakes have rattles? How does the rattle work? 



