The Meaning of Environment 3 



hold of nature is kept in order. Interestingly enough, although 

 ecology comes from the same root as our word "economics," the sub- 

 ject that we now call ecology was not given a name until a century 

 later. Man, being egocentric, began this type of study in his im- 

 mediate surroundings. Not until long afterwards did he realize that 

 man's economics is but a special case of the broader subject. In the 

 words of Wells, Huxley, and Wells (1939), "Ecology is really an ex- 

 tension of economics to the whole world of life." Economics and 

 sociology might be thought of as the "ecology of man" in a broad sense. 

 The realization that the relations of man to his environment, both 

 physical and social, form a distinct and most important study is re- 

 flected in the increasing use of the term human ecology in sociology 

 and in other fields. 



Our goal m ecology is to understand the interrelations of organisms 

 and their environments tinder natural conditions. Many biologists 

 of all sorts have tended to lose this point of view. As Elton ( 1939 ) 

 stated, "The discoveries of Darwin, himself a magnificent field 

 naturalist, had the remarkable effect of sending the whole zoological 

 world flocking indoors, where they remained hard at work for fifty 

 years or more, and whence they are now beginning to put forth cau- 

 tious heads again into the open air!" Laboratory tests and field ex- 

 periments are, of course, used in studying the reactions of animals and 

 plants as an aid to understanding their actual and possible behavior 

 under natural conditions. Modern ecology thus goes beyond the mere 

 description of the habitat, or the listing of its inhabitants, to an anal- 

 ysis of causal relationships and a coordinated understanding of con- 

 structive and destructive processes in the community. 



THE MEANING OF ENVIRONMENT 



In referring to the natural environment one tends to think first of 

 the broad aspects of the landscape, such as water, soil, desert, or 

 mountain. These types of environment can be more exactly described 

 in terms of physical influences— differences in moisture, temperature, 

 texture of material, and the like— and of biological influences. Other 

 organisms form part of the environment just as much as the soil or the 

 rocks. No animal can live entirely as a hermit; every animal must 

 have other organisms within its range to serve as food. All animals are 

 dependent directly or indirectly upon green plants. Many plants are 

 dependent upon animals— those that require pollination by insects, for 

 example. Some green plants could live independently for a time, 

 deriving their energy from the sun and their nutrients from the soil, 



