INHERITANCE OF TRAITS ASSOCIATED WITH SKIN COLOR. 35 



occasionally blue, which indicates that persons with brown eye color 

 may carry germ-cells without the factor for iris pigment ; but from two 

 dark brown parents, or even a dark brown X brown union no blue- 

 eyed offspring are recorded. This result supports the hypothesis that 

 dark eye color rarely forms "blue-eyed" germ-cells; that light brown 

 and hazel represent the heterozygous forms of eye color. 



II. Hair Color. 



In studying the heredity of hair color we have first to recognize 

 that hair pigment has a development and, consequently, the reported 

 condition of a young child can not be compared with that of its parents. 

 Thus, as Holmes and Loomis (1909, p. 55) point out, there are twice 

 as many light brown children under 16 as over, but only half to one- 

 third as many blacks under as over 16 years. The typical hair color 

 of white infants is flaxen; only slowly, if at all, is the mature dark 

 brown acquired. In the case of the Bermudian and Jamaican hybrids 

 much testimony was gathered as to the development of the pigmenta- 

 tion of the hair of the head. Thus it was repeatedly stated that a 

 black-haired person was tow-headed as a child, or a two-year-old boy 

 who has now dark brown hair formerly had it golden ; not infrequently 

 the hair of a one- or two-year-old child was much darker at the base, 

 indicating an increasing activity in the production of hair pigment. 

 On the other hand, there is some testimony to show that the hair at 

 birth is often black; that the permanent hair, which soon appears, is 

 flaxen, to become darker as the child develops. For example, in pedi- 

 gree B 8, Mrs. J. has dark brown hair and Mr. J. has black hair; both 

 are colored. All of their children were born with black hair, which 

 began to lighten in a few weeks, except the youngest child's. The 

 hair color of the children is now as follows: (1) 11 years old, medium 

 brown; (2) 8 years, light brown, golden about her face; (3) 7 years, 

 light brown, golden about her face ; (4) 2 years, dark brown. 



Pedigree B 25, cf, 3 years old. Hair was dark brown when born; became 

 lighter, is now light brown with golden curled ends. A cousin of the fore- 

 going, 9 months old, had black hair when born, but it was replaced by bright 

 red hair. 



Pedigree B 27, 9,4 years old. Her hair was nearly black when she was 

 born; it came in lighter and is now growing dark again (medium brown). 



Pedigree J 10. All 3 children were born with black hair. (1) 9,4 years, 

 light brown hair; (2) 9 , 2^2 years, flaxen; (3) cf , 1 year, reddish-golden hair. 



Dr. J. H. Shawe, of Huntington, N. Y., a family physician of 

 large experience, who has attended at labor many mothers belonging 

 to a great range of nationalities, states that while the infants of Scandi- 

 navian stock have always light head hair at birth, those of South 

 Italian stock usually have black hair at birth. About the color of the 

 young permanent hair in these Italians he was unable to say anything. 



