Cannon and Rosanoff: Heredity of Insanity 11 



The speaker said it was very important to establish clearly the rela- 

 tion between neuropathic and psychopathic heredity. That was also a 

 point of which we knew very little. Some writers would include suicide 

 in the list of psychopathic heredity; others apoplexy, others chorea, and 

 so on. We should define what factors were of importance in psychopathic 

 and what in neuropathic heredity. It had been shown, for example, that 

 normal persons showed a stronger heredity as regarded apoplexy than 

 did insane ones, so that apoplexy, as an etiological factor in insanity, lost 

 much of its meaning. 



Dr. Rosanoff, in closing the discussion, agreed with Dr. Davenport 

 as to the methods which contributed to the value of the data presented, 

 namely, the employment of " field workers " to collect such data, and the 

 application of the Mendelian laws in their interpretation rather than their 

 treatment by ordinary statistical methods. 



As to the role played by environment. Dr. Rosanoff thought that the 

 results of heredity studies did not exclude factors of environment from 

 the etiology of mental disease, but rather added evidence to show their 

 importance. In the material which formed the basis of the paper, prac- 

 tical findings did not correspond exactly with theoretical expectation, and 

 the excess over expectation was always on the side of normal offspring. 

 It would seem that the neuropathic makeup was a character which pre- 

 sented shades of variation as numerous as those in the depth of brown eye 

 color, hair color, etc. While in some instances the neurcfpathic makeup 

 was so well marked as to be plainly manifest from birth, in others it 

 consisted of nothing more than an undue lack of mental balance which 

 resulted in attacks of insanity consequent upon comparatively trivial 

 causes, such as, for instance, childbirth, a moderate indulgence in alcohol 

 or some psychical shock. 



As to the question raised by Dr. Onuf, namely, what diseased condi- 

 tions of the nervous system shall be regarded as manifestations of the 

 neuropathic character which was transmissible by heredity, the speaker 

 thought Dr. Onuf was right in suggesting that conditions exogenous in 

 origin should be excluded, and that apoplexy was in all probability one of 

 these conditions. 



