CHAPTER IV 



INFLUENCE OF ENVIRONMENT 



The development of an individual or the 

 evolution of a race is dependent upon the in- 

 teraction of two sets of factors or causes, the 

 intrinsic and the extrinsic. The former are rep- 

 resented by the organization of the germinal 

 protoplasm, the latter by all other conditions; 

 the former are known as heredity or constitu- 

 tion, the latter as environment or education; 

 or in the words of Galton, these two sets of 

 factors may be called "nature" and "nurture." 

 The great problem of development is the un- 

 raveling of these two factors, the assignment 

 of its true value to each, and the ultimate con- 

 trol of development so far as this may be pos- 

 sible through the knowledge thus gained. 



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