CHAPTER IX 



ENVIRONMENT AND VARIATION 



In observation of animal life it appears that by a process 

 of heredity, the form and structure and physical nature 

 generally, of any creature, is an equipment received from 

 ancestors who have found it advantageous, and therefore 

 have prospered and cultivated it, and transmitted to de- 

 scendants. The mysterious method of transmission will be 

 further studied in later chapters upon evolution. But it is 

 desirable now to seek for an understanding of how such 

 structure and equipment begin and how they come into 

 being, as matters to be thus tested and appreciated and 

 exercised and transmitted. We have already seen their 

 existence but now it is desirable to know their origin; as 

 the origin and transmission of new phases of conduct is 

 obviously involved, being inseparably connected with the 

 use and exercise of those physical gifts. 



We find that all that an animal possesses in the way of 

 bodily structure and equipment, is shaped and patterned 

 after some of its ancestors, with unfailing and amazing 

 accuracy ; in its minutest details, such as number of scales, 

 and patterns of coloring, as well as in the greater features 

 and general form. It should be noted that many ancestors, 

 not simply two parents — contribute these influences. Now 



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