MAN 



159 



behaves as a simple 

 dominant to the 

 normal form, i.e. 

 that it depends 

 upon a factor which 

 the normal does 

 not contain. The 

 recessive normals 

 cannot transmit the 

 affected condition 

 whatever their 

 ancestry. Once 

 free they are always 

 free, and can marry 

 other normals with 

 full confidence that 

 none of their chil- 

 dren will show the 

 deformity. 



The evidence 

 available from pedi- 

 grees has revealed 

 the simplest form 

 of Mecfelian in- 

 heritance in several 

 human defects and 

 diseases, among 

 which may be men- 

 tioned presenile 

 cataract of the eyes, 

 an abnormal form 

 of skin thickening 

 in the palms of the 



**- 



L**_+ 



