32 Heredity and Social Progress 



5. The order of the change from acquired to natural 

 characters is : first, the production of surplus energy through 

 acquired characters ; second, the expression of this energy 

 in the secondary characters ; third, the discovery of some 

 use for these secondary characters in which all the species 

 can share, and then the movement of the species into an 

 environment where these secondary characters are necessary 

 and hence primary. 



