EYE COLOR AND HAIR COLOR IN MAN. 65 



may be associated with light color of eyes but light hair is not 

 associated with dark color of eyes. Light-haired individuals, if 

 adults, are pretty sure to have eyes of the blue or gray type, with 

 little melanin pigment. 



The data in Table IV. show that the inheritance of the corre- 

 lation of hair color and eye color is not very strong. In the first 

 column is given the number of matings in which certain combina- 

 tions occur ; in the second, the number of cases among these 

 matings in which the combination appears in the offspring ; in 

 the third, the number of cases in which the combination occurred 

 in which it failed to be transmitted. Black eyes and black hair 

 both behave as dominant characters, but it frequently happens 

 that parents, one of whom has black eyes and black hair, will 

 produce a child with black hair and blue eyes, although they 

 will not produce one with black eyes and light hair. We cannot 

 be dealing here with two independently mendelizing characters, 

 because the independence is purely a one-sided one. 



Summary. 



1. In the inheritance of the color of hair and eyes, the more 

 pigmented condition tends to be dominant over the less pigmented. 



2. Crosses of more darkly pigmented types produce a number 

 of dark types as well as a number of lighter ones, but crosses of 

 the lighter types rarely produce darker ones. 



3. Inheritance of eye color and hair color, although partly 

 alternative, conforms to a certain extent to the blended type. 



4. There is a certain amount of evidence that the pigmentation 

 of eyes and hair may exceed that of both parents, especially 

 when both parents are pigmented to the same degree. 



5. Dark hair may be associated either with dark eyes or light 

 eyes, but light hair does not occur along with darker eyes. 



6. Correlations of hair color and eye color are not strongly 

 inherited. 



