INHERITANCE OF MENTAL DEFECTS AND DISEASE 53 
tion. It certainly seems remarkable that many kinds of germinal 
defect would give rise to the same sort of neuropathic disorder. 
If so, one person might lack something necessary to normality 
and another person might lack something else, and yet the union 
of these persons might supply all that was needed to make a 
normal product. This would be clearly possible if the defects in 
question were completely recessive. One might expect, therefore, 
in view of the varied nature of hereditary insanity, that two 
insane, or at least two neuropathic persons might occasionally, if 
not frequently, produce a normal individual. The probability of 
such an occurrence would obviously depend upon the number of 
affected units in the germ plasm of the two persons, and the 
genetic similarity of the two types of hereditary defect. It would 
be of especial interest to compare the matings of similar neuro- 
pathic defectives on the one hand and dissimilar types on the 
other. Whether or not the latter types especially may not yield 
normal offspring we are not at present sufficiently assured. Mat- 
ings of neuropathic and neuropathic, it is true, will produce a 
large proportion of neuropathic offspring. In the three cases of 
this kind given by Cannon and Rosanoff the parents were simply 
designated neuropathic, a term used to cover hysteria, feeble- 
mindedness, epilepsy, convulsions or other pronounced manifes- 
tations, and the children of these matings which were all marked 
neuropathic showed insanity, epilepsy, convulsions and neuro- 
pathic states not further specified. In a paper by Rosanoff and 
Orr 17 such matings are recorded, resulting in 75 children of whom 
11 died in infancy, 54 of the remaining 64 are given as ‘‘neuro- 
pathic,” 10 being designated normal. In these 1o the authors 
state that in 2 cases “the neuropathic constitution is not insan- 
ity,” and that the 8 others “have not reached the age of in- 
cidence.” 
There are several cases in which insane parents have been 
reported to have produced sane offspring. Pearson’s family 
records give 66 per cent. insane offspring when both parents are 
insane. Only those children were classed as sane who reached an 
age of 50 years without developing insanity. Acquired insanity of 
