Phenomena of Inheritance 71 



tional and extreme individuals but by the average or mean quali- 

 ties of the race; and measured in this way there is no doubt that 

 certain types of mind and disposition are characteristic of certain 

 families. 



There is no longer any question that some kinds of f eeble-mind- 

 edness, epilepsy and insanity are inherited, and that there is often 

 an hereditary basis for nervous and phlegmatic temperaments, for 

 emotional, judicial and calculating dispositions. Nor can it be 

 denied that strength or weakness of will, a tendency to moral 

 obliquity or rectitude, capacity or incapacity for the highest in- 

 tellectual pursuits, occur frequently in certain families and ap- 

 pear to be inherited. In spite of certain noteworthy exceptions, 

 which may perhaps be due to remarkable variations, statistics col- 

 lected by Galton show that genius runs in certain families ; while 

 the work of some recent investigators, particularly Goddard, 

 Davenport and Weeks, proves that f eeble-mindedness and epilepsy 

 are also inherited; and the careful work of Mdtt and of Rosanoff 

 indicates that certain types of insanity are hereditary. On the 

 other hand, Cotton maintains that mental disorders are not di- 

 rectly inherited, but that "there is probably a constitutional lack 

 of resistance to various toxins and poisons, and not an inherited 

 mental instability, which causes the mind to break down under 

 mental stress and strain." It frequently happens that families 

 in which hereditary insanity occurs also have other members 

 afflicted with epilepsy, hysteria, alcoholism, etc., which seem to 

 indicate that the thing inherited is an unstable condition of the 

 nervous system which may take various forms under slightly 

 different conditions. Indeed there is a good deal of evidence that 

 extraordinary ability, or genius is frequently associated with an 

 unstable nervous organization which sometimes takes the 

 form of insanity or epilepsy or alcoholism. There is perhaps 

 more truth than poetry in Dryden's lines: 



"Great wits are sure to madness near allied, 

 And thin partitions do their bounds divide." 



