vi PREFACE. 



at variance with the opinion of his revered father, 

 who aided his great theory by the retention of 

 some remains of Lamarck's doctrine of the in- 

 herited effect of habit. I feel as if the son, as 

 representative of his great progenitor, were carry- 

 ing out the idea of an appreciative editor who 

 writes to me : " We must say that if Darwin were 

 still alive, he would find your arguments of great 

 weight, and undoubtedly would give to them the 

 serious consideration which they deserve." I 

 hope, then, that I may be acquitted of undue 

 presumption in opposing a view sanctioned by 

 the author of the Origin of Species^ but already 

 stoutly questioned and firmly rd|ected by such 

 followers of his as Weismann, Wallace, Poulton, 

 Ray Lankester, and others, to say nothing of its 

 practical rejection by so great an authority on 

 heredity as Francis Galton. 



The sociological importance of the subject has 

 already been insisted on in emphatic terms by 



