6 THE PROBLEMS OF EVOLUTION 



r^sultat predetermine,"^ yet the Hagedoorns^ find 

 it necessary to warn us that scientists have not 

 approached the problem with open minds in apply- 

 ing the results of their researches and show little 

 evidence of doing so now. And still when we have 

 recognized and admitted that the heritage and the 

 environment are inseparable, we are scarcely nearer 

 to a solution of our problem than before. We wit- 

 ness their interaction only in the individual and 

 the diflSculty has always been to determine if, and 

 how, the transition might occur from the somatic 

 characters admittedly produced in the individual 

 to the hereditary characters which appear nor- 

 mally in all individuals of a species. We are left 

 with several fundamental concepts to clarify; 

 among them the relationship of individual and 

 species, and the consequent association of heritage 

 and environment in the two entities, are prominent. 

 Once we acquire a satisfactory attitude toward 

 these fundamental questions, the difficulties pre- 

 sented by the apparently sound theories of evolu- 

 tionary method are lessened. It becomes obvious 

 that whether we deal with orthogenesis, mutation, 

 natural selection, or any of the minor methods of 

 change, a uniform analysis on the basis of interact- 

 ing heritage and environment is possible. Whereas 

 these theories have overemphasized one or another 



« Biologica, Vol. Ill, p. 171, 1913. 



* The Relative Value of the Processes Causing Evolution^ 1921. 



