THE AMPHIBIA 171 



eject their sperm over the egg masses as soon as they are 

 extruded from the body of the female. The eggs once 

 laid and fertilized, the frogs leave the water and resume 

 their active predatory life. The long months of hiberna- 

 tion, when life was supported only by the food materials 

 stored up in the tissues, leave the frogs lean and hungry, 

 especially after the additional burden of maturing the re- 

 productive cells. Life in the winter except in warm cli- 

 mates is spent in a dormant state, when the temperature of 

 the body runs down and the vital activities become very 

 sluggish. Frogs which are partially frozen until their 

 legs are so brittle that they can be broken like icicles may 

 subsequently revive, provided they are very slowly thawed 

 out; if, however, they are frozen solid throughout they 

 never regain life. 



It is in the spring that the frogs make the most music. 

 Ordinarily it is the males that do the croaking and it is 

 supposed that the voice serves as a call, like the chirping 

 of the male cricket, for bringing the sexes together. 

 In some frogs the males have a pair of vocal sacs opening 

 into the throat, which become inflated during the act of 

 croaking. In others, as in the tree frogs, the production 

 of sound is accompanied by a distension of the floor of 

 the throat. The male toad produces only a relatively 

 faint but peculiarly musical trill. 



Frogs and toads are not particularly choice of what they 

 eat, as they devour all sorts of insects, worms and other 

 small creatures, but they are very peculiar in their methods 

 of food taking. They are furnished with an extensile 

 tongue which is joined to the front of the lower jaw and is 

 capable of being thrust out of the mouth and withdrawn 

 again with great quickness. Should an insect or worm be 

 moving near by, the tongue may be shot out and the prey 

 drawn back into the mouth, and quickly swallowed. It 



