INTRODUCTION 5 



evolutionary method, and all existing theories may 

 be disposed on one or the other side. They neither 

 decide nor abate the controversy. 



If this quarrel between the proponents of en- 

 vironment as the important shaping factor in the 

 origin of species and those of the heritage appealed 

 to me as valid, I should have nothing further to 

 say, for in that case our present knowledge would 

 be insuflficient to decide the matter and further 

 argument would be as profitless as that of the past. 

 Rather, it appears that we have been barking up 

 the wrong tree and that the promising field for 

 investigation is not the relative merits of these two 

 factors but their universal and exceedingly intri- 

 cate coordination. This point of view is not orig- 

 inal, but since it came to me without direct sug- 

 gestion from others I derive a firm conviction of 

 its soundness from the similar conclusions that I 

 find scattered through the literature. It presents 

 difficulties of its own. Perhaps it will not lead us 

 yet to an ultimately tenable conclusion, but as an 

 initial step it seems inevitable. 



This point of view is slow to gain a hearing. 

 Conklin ^ years ago emphasized the inseparability 

 of heritage and environment. Rabaud states an 

 undeniable truth in saying: "Des maintenant, 

 nous pouvons aflSrmer que ni le milieu ni I'orga- 

 nisme consider^s isolement ne portent en eux de 



' Heredity and Environmeni, First Edition, 1915. 



