134 The Third and Fourth Generation 



at least a segregation of feeble-minded in this 

 country, even if no more drastic action is taken. 

 Otherwise the group is bound to be an increas- 

 ing burden on the community, adding con- 

 stantly to the tax needed for their support. 



Investigations of competent officials in the 

 employ of insane hospitals have accumulated 

 a mass of evidence demonstrating the heritabil- 

 ity of many forms of nervous diseases which 

 most commonly behave as recessives. Rosanoff 

 and Orr,' in a study of 206 matings between 

 individuals from more or less insane stock, 

 found 1,097 children, 146 of whom died in 

 childhood. There were 351 afflicted offspring 

 to 586 normal. The theoretical expectations, 

 knowing with more or less certainty the char- 

 acter of the parents, was 359 to 578. There 

 are presented (Figs. 12, 13, p. 135) two typical 

 family pedigrees. In the first an insane man 

 was twice married, each time to an eccentric 

 woman, undoubtedly mildly insane. All the 

 offspring were unbalanced. In the second case, 



' Eugenics Record Office (Cold Spring Harbor, N.Y.), 

 Bulletin, No. 5, 191 1. 



