THE INHERITANCE OF FAMILY TRAITS 171 



strain have normal sons. But occasionally apparently nor- 

 mal fathers in whom the "inhibitor" is inactive may have 

 abnormal sons (Fig, 151.) The eugenical conclusion is that 

 females belonging to hermaphroditic (hypospadic or cryp- 

 torchitic) strains, if married, will probably have at least half 

 of their sons defective, particularly if they have defective 

 brothers; but normal males of such strains may marry fe- 

 males from unaffected strains with impunity. 



I 



w 



w 







Fig. 151. — Pedigree of hypospadias (black symbols). Inheritance from 

 affected males and unaffected females, III, 2. Lingard, 1884. 



c. Prolapsus of the Uterus and Sterility.— Corresponding in 

 a way with incomplete development of the male reproduc- 

 tive organs is the prolapsus of the uterus in the female. This 

 is also definitely inherited but the trait is never transmitted 

 by affected females since they are sterile (Fig. 152). 



40. Skeleton and Appendages 

 Since the size and form of the bodily frame are greatly 

 influenced by the skeleton the heredity of these features is 



