GETTING ACQUAINTED WITH THINGS 



Photo by U. S. Forest Service Orient and Occident Photo 



What factors of the environment are alike in these pictures? Which are different? 



N. Y. Times and St. Louis 

 Post Dispatch 



knowledge it would be difficult to prove that plants and 

 animals use in one way or another all of these forces and 

 things which surround them, but such is the case. The 

 bird in the air, the fish in the water, the tree in the ground 

 - all living things use some part of the air, water, a 

 favorable temperature, light, and some kind of supporting 

 substance, as the soil, in order to live. Hence we call 

 these the factors or parts of the environment. 



Living things depend upon the factors of the environ- 

 ment. We could easily prove that these factors of the 

 environment were necessary for life by simple experiments. 

 A fish will die out of water, and no animal or plant will live 

 long without this important substance. If the plant or 

 animal were placed in a jar from which it could exhaust 

 the air, we would find that it woujd die as soon as the air 

 supply was cut off. Light is essential to most living 

 things, for all green plants and most animals prefer light. 

 Some require much heat ; others, like the polar bear, pre- 

 fer a cold climate. Some plants can exist in temperature 

 which would mean death to others. And all living things 

 find some support necessary for their bodies, usually either 

 water or soil. We know that living things need and use 

 factors of their environment, but how they use these 

 factors is much more difficult to understand. 



