268 THE FITNESS OF THE ENVIRONMENT 



a. Complex (physically, chemically, 



physiologically) . 



b. Durable, hence well regulated 



physico-chemically. This con- 

 clusion applies to — 



1. The Organism. 



2. The Environment. 



c. Endowed with a metabolism. 



Hence there must be ex- 

 change with the environment 

 of — 



1. Matter. 



2. Energy. 



III. The primary constituents of the natural 



environment are — 



a. Water. 



b. Carbonic acid. 



IV. In places where life is possible the 



primary constituents of the 

 environment are necessarily 

 and automatically formed in 

 vast amounts by the cosmic 

 process. 

 V. Water, carbonic acid, and their con- 

 stituent elements manifest 

 great fitness for their biologi- 

 cal role. 

 a. Water possesses a great number of 

 unique or very unusual prop- 



