258 LIVING THINGS IN THEIR ENVIRONMENT 



live. If you think for a moment, you will see why this 

 statement is true. Try to think of some animal that 

 lives on flesh alone such as a lion or tiger. But it 

 preys on cattle, deer, antelope, and other grass-eating 

 animals. Or take a big trout that lives upon smaller 



meat 



zesting 



animals 



kUl and 

 eat- 



eater 



plants 

 make fooctfw- 



all the earth. 



The food cycle. Follow it through and try to prove that green plants make 

 the food of the world. 



fishes, insects, and insect larvae. In every case the food 

 of the smaller animals can be traced to the green plants. 

 Everywhere in nature we find that green plants form the 

 basis of the world's food. The great flour mills merely 

 change the raw food materials made by the wheat plant 

 into a form that we prefer to eat. Other animals like 

 cattle eat the food as the plant makes it. See if you can 

 find any cases of animals that do not depend on plants for 

 their food, and bring the case up before the class for dis- 

 cussion. 



How Are Plants Fitted to Do Their Work? Everyone 

 is familiar with a green plant. We all know it has roots 

 which hold it in the ground, an upright stem which bears 

 the green leaves, and sometimes flowers which form fruits 



