228 A STUDY OF HEREDITY IN INSANITY [Oct. 



theoretically all should be neuropathic. Of these ten one died at 

 the age of thirty-eight years in an accident, during life suffered 

 from asthma, had a son who died in convulsions; another is 

 described as being easy going, is somewhat odd and possibly 

 abnormal in" make-up, is twenty-nine years of age ; the rest are 

 from eight to twenty-two years of age. In other words, in two 

 of the ten subjects the neuropathic constitution is not positively 

 excluded and the remaining eight have not reached the age of 

 incidence. 



The matings of the second and fourth types, DRxRR and 

 DRxDR respectively, have been divided into two groups each, 

 as already explained in the preceding section : thus groups b and 

 d in the chart include the matings in which the simplex condition 

 of either or both mates, as the case may be, is definitely ascer- 

 tained, the existence of neuropathic manifestations either in an- 

 cestors or in collateral relatives of the subjects appearing in the 

 pedigrees ; groups fe^ and d^, on the other hand, include the 

 matings in which the simplex condition of either or both mates is 

 assumed to exist on the basis of the character of the offspring. 

 It is perhaps not surprising that groups b^ and rfi are larger than 

 b and d respectively when we consider the great likelihood of a 

 neuropathic taint, derived from an ancestor of a remote genera- 

 tion, being transmitted many times in the shape of a simplex 

 condition, and at the same time the fact that our investigations 

 extended in almost all cases no farther back than the generation 

 of grandparents. 



As is shown in the table the correspondence between theoretical 

 expectation and actual findings is in some cases exact and in all 

 cases remarkably close. It would seem, then, that the fact of the 

 hereditary transmission of the neuropathic constitution as a reces- 

 sive trait, in accordance with the Mendelian theory, may be 

 regarded as definitely established. 



The material represented in the table appears elsewhere in this 

 paper in the shape of pedigree charts with detailed references to 

 all neuropathic individuals. Among the subjects who have been 

 counted as neuropathic were, on the one hand, those who were 

 recognized as insane, epileptic, hysterical, or feeble-minded, and 

 on the other hand, those who presented anomalies of conduct or 

 disposition which were even in the conservative judgment of our 



