2QO 



made to separate the effect of the children's use of tobacco and 

 liquor, which he claims are deplorably prevalent, from the effects 

 possibly due to heredity. The papers of MacNicholl belong to 

 that very large class of literature on the hereditary influence of 

 alcohol which neglects nearly all of the elementary precautions 

 which are absolutely essential for attaining reliable results. 



From the kind of data we have on the hereditary effects of 

 alcohol in human beings it is difficult to come to any positive 

 conclusion. And there is a much less confident tone in the utter- 

 ances on this subject among more recent authorities on heredity 

 than there was several years ago. It is commonly recognized that 

 in certain families there is a bent toward alcoholism. This no 

 more proves that such a trait is the result of the liquor habit than 

 the reappearance of kleptomania proves that this failing is the 

 result of parental thieving. What caused the original appearance 

 of the bent toward alcoholism we do not know. Neither do we 

 know in most cases what causes the first appearance of feeble- 

 mindedness and the hereditary forms of epilepsy and insanity. 

 When the attempt is made to follow the history of these maladies 

 we usually uproot a strain of defective inheritance which runs 

 back and back farther than we can trace it. The Jukes, the Tribe 

 of Ishmael, the KaUikak family, the Zero family and the Nam 

 family all have much the same melancholy sort of history. All 

 show alcoholism and degeneracy going hand in hand. It is 

 reasonably certain that much alcoholism is the product of degen- 

 eration. That it is a common cause of the first appearance of 

 degenerate strains is of course possible, if not probable. But 

 our present knowledge of the subject does not justify us in assert- 

 ing that such a conclusion is anything more than a good working 

 hypothesis. 



There is no question in eugenics more important than that of 

 the origin of defective strains of human beings. How much light 

 might be thrown on the problem by statistical investigation, if 

 undertaken in the right way, I shall not presume to predict, but 

 so far as the hereditary influence of alcohol is concerned the most 

 promising method consists in experiments on animals. In this 



