.THE HEREDITY OF EYE COLOR AND HAIR 

 COLOR IN MAN. 



S. J. HOLMES AND H. M. LOOMIS. 



Since the present study was begun several papers have ap- 

 peared dealing with the subject matter of our investigations. 

 Much of our data corroborates the conclusions expressed in these 

 papers. In some cases the facts seemed to warrant some differ- 

 ences of opinion in regard to certain theoretical matters, and it 

 was therefore deemed advisable to present the data obtained and 

 the conclusions that appeared to be deducible therefrom. 



The data were collected by sending out printed forms with 

 headings under which to designate the eye color and hair color 

 of each parent, grandparent and child and the age and sex of each 

 of the children of the family. If the children came from parents 

 one or both of whom were married more than once the exact re- 

 lation of the various individuals was stated. Eye color was 

 classed as blue, green, gray, hazel, brown and black, and hair 

 color as yellow, light brown, dark brown, black, red and auburn. 

 The printed forms were distributed mainly to the students of the 

 University of Wisconsin with the request that so far as possible 

 t-hey fill them out in consultation with their parents during the 

 holidays. Fairly complete data were received from 71 families 

 including 406 individuals. While the data are not extensive nor 

 free from sources of error they are, I think, sufficiently complete 

 and reliable to enable one to draw several conclusions which have 

 a high degree of probability. 



Eye Color. 

 The color of the eyes is due to the factors causing blue, a dark 

 brown granular melanin pigment, and in such cases a yellow pig- 

 ment which is possibly a lipochrome. Blue is often darker in 

 the young. "The darker shades of blue," according to Hurst, 

 ■" are apparently due to the greater delicacy and transparency of 

 the fibrous tissues of the iris through which the posterior pigment 



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