i27!2 



GENETICS AND EUGENICS 



TABLE 33 

 Inherited Characters in Man 



1. Blending 



General body size, stature, weight, skin-color, hair-form (in cross-section, corre- 

 lated with straightness, curliness, etc.) shape of head and proportions of its parts 

 (features). 



2. Mendelian 

 Dominant 



Skin and hair 



Dark. 



Spotted with white. 



Tylosis and ichthyosis (thickened 

 or scaly skin). 



Epidermolysis (excessive forma- 

 tion of blisters). 



Hair beaded (diameter not uni- 

 form). 



Recessive 



Blonde or albino (probably 



multiple allelomorphs). 

 Uniformly colored. 

 Normal skin. 



Normal skin. 



Normal hair. 



Eyes 



Front of iris pigmented (eye 



black, brown, etc.). 

 Hereditary cataract. 

 Night blindness (when not sex 



limited). 

 Normal. 



Only back of iris pigmented 



(eye blue). 

 Normal. 

 Normal. 



Pigmentary degeneration of 

 retina. 



Skeleton 



Brachydactyly (short digits and 



limbs). 

 Polydactyly (extra digits). 

 Syndactyly (fused, webbed, or 



reduced number of digits). 

 Symphalangy (fused joints of 



digits, stiff digits). 

 Exostoses (abnormal outgrowths 



of long bones). 

 Hereditary fragility of bones. 



Normal. 



Normal. 

 Normal. 



Normal. 



Normal. 



