Heredity, Variation and Genius 85 



patent to all the world, but also of the members 

 of the family in which it is not manifest and of 

 their several peculiarities and life-issues — that is a 

 study which might do more to shed light on the 

 facts of human heredity than all that has ever yet 

 been vaguely written on the subject under the 

 guise of information. How little is learnt by 

 learning that one child of an insane parent be- 

 comes insane when the characters and fortunes 

 of other children of the same parent who do not 

 become insane are not traced ! A transformation 

 of morbid neuroses notoriously takes place through 

 generations, the epilepsy of one generation being 

 the insanity or idiocy of the next generation, and 

 one form of insanity in the parent coming out as 

 another form of insanity or perhaps as a form of 

 crime in the offspring. It is again a positive fact 

 of observation that side by side in the same family 

 there shall be a person of distinguished talent or 

 perhaps genius, and another who is a confirmed 

 lunatic, or commits suicide, or is a hopeless cast- 

 away. In like uncertain manner insanity or other 

 allied nervous disorder occurs not in the following 

 generation yet crops up in the third generation : 

 an instance of hereditary continuity through ap- 

 parent discontinuity. Incalculable are the com- 

 bination-chances of germinal unions not only be- 

 cause of the number and variety of the factors 

 and the exceeding complexity of the process, but 

 because, as exact research after the Mendelian 

 method gives reason to suspect, one factor not 



