INHERITANCE OF MENTAL DEFECTS AND DISEASE 41 



gives 35 per cent, and the 56 per cent of my table coincides with 

 Spratling's record in 1,100 cases." 



The gravity of the disease (it is seldom curable) and its not 

 infrequent connection with some of the worst crimes of violence, 

 render the subject of its mode of transmission of especial impor- 

 tance. The first serious attempt to show that epilepsy is inherited 

 according to Mendel's law was made by Davenport and Weeks 

 who followed up the pedigrees of many of the inmates of the New 

 Jersey State Village for Epileptics at Skillman, N. J. The pedi- 

 grees were obtained mainly by field workers and the data were 

 analyzed according to the assumption that the matings fell into 

 the classes which might be expected to occur in simple Mendelian 

 inheritance. We quote the principal conclusions of the investiga- 

 tion: "Epilepsy and feeble-mindedness show a great similarity of 

 behavior in heredity supporting the hypothesis that each is due to 

 the absence of a protoplasmic factor that determines complete 

 nervous development." 



"When both parents are either epileptic or feeble-minded all 

 their children are so likewise. 



"The conditions named migraine, chorea, paralysis, and ex- 

 treme nervousness behave as though due to a simplex condition 

 of the protoplasmic factor that conditions complete nervous 

 development. . . . 



"When such a tainted individual is mated to a defective about 

 half the offspring are defective. 



"When both parents are simplex . . . and 'tainted' about 

 one-quarter (actually 30 per cent) are defective. 



"Normal parents that have epileptic offspring usually show 

 gross nervous defect in their close relatives. 



"While we recognize that 'epilepsy' is a complex, yet there is a 

 classical type numerically so preponderant that, in the mass, 

 'epilepsy' acts like a unit defect." 



Only one instance is given in which both parents were epileptic 

 and it happened that both were feeble-minded also. Of their four 

 children one was feeble-minded and died before 14; but the other 

 3 all developed epilepsy. In a subsequent paper by Weeks two 



