Morbid Psychological Heredity. 131 



questions that are unfortunately very obscure. The first is this : 

 What rank must we assign to heredity among the causes of 

 insanity ? Good statistical documents alone can afford the answer ; 

 but the various tables agree but little with one another. Cases of 

 hereditary insanity are, according to Moreau of Tours, nine-tenths 

 of the whole number; according to other writers they are only 

 one-tenth. According to Maudsley they are more than one-fourth, 

 but less than half: in 50 cases of insanity carefully examined 

 by him, 16 were hereditary, or one-third. In 73 cases given by 

 Trelat in his Folie Lucide, 43 are represented as due to heredity. 

 From a report made to the French Government in 1861, it appears 

 that in 1000 cases of persons of each sex admitted to asylums, 

 264 males and 266 females had inherited the disorder. Of the 

 264 males, 128 inherited from the father, no from the mother, 

 and 26 from both. Of the 266 females, 100 inherited from the 

 father, 130 from the mother, and 36 from both. Hence we should 

 hardly be in error were we to say that the cases of hereditary 

 insanity represent from one-half to one-third of the total number. 



The second question is this : To what form of mental heredity 

 must hereditary insanity be referred? In the first place, as 

 regards mere, simple hallucination, it is plain that it is only a form 

 of heredity of the sensorial faculties. As for insanity, properly 

 so called, since it assumes every possible shape ; since it presents, 

 now separately, now collectively, perversion of the sentiments and 

 instincts, loss of intellect, and weakness of will ; and since it has 

 never been found possible so far to trace back all the psychological 

 phenomena of insanity to one cause, we may affirm that the fore- 

 going facts are a fresh demonstration, in extenso, of psychological 

 heredity under all its forms. 



