TRANSMISSION OF CHARACTERISTICS 101 



The most important because the most general vice 

 dependent upon the law of heredity is drunkenness. 

 Every writer on physiology furnishes proofs of the 

 existence of hereditary dipsomania, and there are few 

 private individuals who could not point to cases of 

 the kind within their own circle of acquaintances. 

 Like every other physical and mental peculiarity, 

 alcoholism is capricious in its choice of a subject, 

 attacking some member of a family and passing over 

 others ; it must be borne in mind, however, that it 

 assumes various forms, all traceable to a deterioration 

 of the brain and the nerve-system. 



To pass to a more agreeable aspect of the sub- 

 ject, Galton's laborious work on Hereditary Genius 

 proves, to some extent, that just as mental weakness 

 is transmissible, so also is mental power. The one 

 case, indeed, implies the other. If vice is hereditary 

 because of a deterioration of the physical structure, 

 it follows that talent or genius, as the result of a 

 superiority of brain-fibre or nerve, is equally so. 

 Unfortunately Gallon has pushed his theories to an 

 extreme, and has thereby prejudiced the cause of 

 moral heredity with many who are already too prone 

 to reject it. It is twenty years since Hereditary 

 Genius was published, and during that time a great 



