28 LIFE DEPENDS ON ADAPTATIONS 



grass like the grasshopper, or burrow in the ground like 

 the gopher, or withdraw into a protective shell like the 

 snail or turtle, and in hundreds of ways perform actions 

 that result in getting protection from their enemies or 

 food for themselves. In shallow water at the seashore 

 you may have caught little hermit crabs which protect 

 their defenseless bodies by thrusting them into the cast- 

 off shell of a sea snail, and retreating into it in time of 

 danger. Such adjustive actions we also call adaptive, for 

 they result in some good to the animal or plant. 



Some animals are even adapting themselves like man 

 to the changed conditions of modern life. The English 

 sparrow, which used to subsist in our cities very largely 

 on the partially digested seeds in horse and other manure, 

 began to disappear in the cities when automobiles took 

 the place of horses. Now we occasionally see the sparrows 

 perched on the radiators of cars picking out insects which 

 have been caught in these radiators as the cars went 

 through the country highways. 



Adaptations, then, may be structures which help the 

 animal or plant to live, or acts performed by the animal 

 or plant which result in better living conditions. 



The Problems of Living Things. If you will think for 

 a moment, you will see that living things, both plants 

 and animals, have two big problems in life. The first 

 is the care of themselves, the Second the reproduction 

 of young. The business of living means adjusting them- 

 selves to their surroundings so that they may get food, 

 grow strong, and be able to protect themselves from their 

 enemies. No matter what the living thing, be it a fish, 

 a bird, a snail, a tree, or a weed, the problems of living are 

 the same in the end. 



Some Ways in Which a Bird Is Fitted for Its Life Work. 

 Let us take, for example, a robin. You say such a bird 

 is well fitted for its life. It has its legs provided with flexi- 



