359 



INFLUENCE OF ENVIRONMENT 



the same rank of society and in the same 

 country." 



The pai-t played by these different factors 

 of development may be graphically illustrated 

 by the accompanying diagram (Fig. 83), in 

 which the base line represents heredity and 

 the other lines represent the extrinsic factors 

 of environment and education. For each in- 

 dividual heredity is a constant factor but en- 

 vironment and training are variables. With 





',■? 



\%:'' 



•Urn 



Heredity 

 Fio. 83. Diagram to show the influence of heredity, en- 

 vironment and training in the development of an individual. 

 Various types of individuals (represented by the triangles) 

 may be produced from the same ^rm cells (heredity) if the 

 environment and training are variable. 



