THE STRUGGLE TO LIVE 405 



rays, common on the coast, have a strong, jagged 

 spine in the tail, armed with broad saw-like teeth, which 

 inflicts a bad, ragged cut. The torpedoes or electric rays 

 found on the sandy shores of all warm seas have on each 

 side of the head a large honeycomb-like structure which 

 gives a strong electric shock whenever the live fish is touched. 

 Among the reptiles of our country the poisonous bite of 

 the rattlesnake, copperhead, and water-moccasin is a familiar 

 example of a very effective special means of defense. 



Certain special habits of animals, too, help much to pro- 

 tect them, and to save their lives. The migration of birds 

 takes many from a bleak, foodless winter to the luxuriant 

 tropical forests, where there is plenty of food and the weather 

 is mild. The hibernation or "winter sleep" of bears, snakes, 

 and lizards carries them safely through a season when food 

 is scarce or wanting altogether. And some animals .come 

 from their holes and hiding-places to hunt food only at 

 night, when most of their enemies are asleep. 



Finally (as we shall learn particularly in a later chapter), 

 many animals are colored and marked in such manner that 

 they match or fit in so well with the soil or leaves or stones 

 on which they rest as to be indistinguishable. And this 

 scheme of harmonious coloration is one of the most success- 

 ful and wide-spread of all the special protective devices. 



Examples to be looked for by the pupils. Only a 

 few of the special means for food-getting and protection 

 are mentioned in this chapter, and those animals which 

 may be most readily observed by the pupils have purposely 

 not been referred to. When we come upon such a peculiar 

 device as the long neck of the giraffe or the fishing-pouch of 

 the pelican our attention is specially attracted, and we are 

 likely to consider such cases unusual and exceptional. But 

 they are not exceptional, they are simply unusual and un- 

 familiar and specially conspicuous. All animals, including 

 all those we know best, have special means of food-getting 



