THE INHERITANCE OF FAMILY TRAITS 127 



afi' 



OiO 



N N N ^ 

 No deaf descendants 



in~~i^^ii 



n 



N N 



I Deaf Mute* 



N 



Dp 



N 



an 



Fig. 96. — Three sisters (Gen. Ill), deaf mute from birth, had several per- 

 fectly normal brothers and sisters. Their mother's uncle had been a con- 

 genital deaf mute. The first sister married a hearing man and had 3 children, 

 i hearing son and 2 mute daughters, who married hearing men and had 

 only hearing children. The second sister was educated and married an edu- 

 cated mute but died soon after the birth of her normal child. The third sister 

 married, first a hearing man and had a normal daughter whose children were 

 in turn normal. But she married for a second husband a deaf mute belonging 

 to a fraternity with 2 other deaf mutes and all 4 children who survived 

 infancy were deaf mutes. Report, N. Y. School for Deaf and Dumb, 1853, 

 p. 96. 



a 



cousins 



1111111 1 I I I I I I I I I I I I 

 N N N N N D IH-^D DDDNNNNNNNN 



mn IN t I J J J I . 



N NNNND 



¥D »T#D i^i D mf 

 ri m rrr 



D NNNN NNN 



51 



rrn 



NNNN 



Fig. 97. — Pedigree of deaf mutes — black symbols or D. Note the fraternity 

 of deaf mutes derived from the central mating of cousins. Most of those who 

 outmarried, even though their consorts were deaf, had hearing children. 

 Fat, 1898, No. 810. 



In view of the foregoing data the first eugenic recommen- 

 dation clearly is that two deaf mutes should not have chil- 

 dren, especially if they come from the same long-settled 

 community or are known to be blood relatives. 



