64 GENETICS 



interminable question," is not simply an academic 

 matter. Its solution is of vital importance from sev- 

 eral viewpoints. For breeders, who are trying to 

 maintain or improve particular strains of animals or 

 plants ; for physicians, who, in fighting disease, are 

 honestly seeking to substitute an ounce of prevention 

 for a pound of cure ; for sociologists and philanthro- 

 pists, who have at heart the permanent bettering of 

 human conditions; for educators, who cherish hopes 

 that their life-work of unfolding the youthful mind 

 may prove cumulative and lasting rather than tran 

 sitory; for religious workers, who want their faith 

 strengthened that conquests in character-building may 

 outreach the individual and so enrich the race; for 

 parents, who entertain hopes that their own efforts 

 may give their children a better biological start in 

 life, for all these and many more, it is important to 

 know the answer to the question: Can acquired 

 characters be inherited? 



4. AN HISTORICAL SKETCH OF OPINION 



That the personal accumulations of a lifetime are 

 heritable was generally believed throughout the credu- 

 lous ages. A century ago Lamarck made this idea 

 the corner-stone of his theory of evolution. It was all 

 very simple. The reason evolution occurs in nature 

 is because individual acquirements are being continually 

 added to the onflowing stream of living forms. This 

 cumulation of characters indeed is evolution. How 

 else can the present stage of adaptation of organisms 



