462 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1921. 



(5) There are red-haired individuals in whom the depigmentation 

 involves the whole system, approaching more or less albinism and 

 an abnormal condition. 



(6) There is no line of demarkation between red hair and golden 

 on one side and red hair and the different shades of brown on the 

 other. 



ANOMALIES OF HAIR TIGMENTATION. 



Anomalies of hair pigmentation relate to uniformity in color and 

 premature or delayed grayness. But little in these respects was no- 

 ticed among the Old Americans, if we disregard slight to moderate 

 irregularities in shading (lighter or darker strands). 



Two individuals, however, one male and one female, showed dif- 

 ferent colored tufts (or locks) of hair. The female had a white 

 lock in dark hair above the forehead; the male a black tuft in other- 

 wise uniform medium hair above the fore part of the right temporal 

 region. In one female 45 years old most of the hair on the right 

 side was medium brown, while the whole left side was (naturally) 

 perceptibly darker. 



THE EYES. 



To properly gauge the eye color is a fairly simple matter in some 

 groups of the white race, such as the pure Nordics or the Mediter- 

 raneans, but it becomes a difficult task in mixed strains, such as that 

 of the English and especially the Americans. 



To approach the subject properly we should be clear to start with 

 on the elementary question as to what is eye color. The many shades 

 of eyes to be met with, as with the hair, do not represent so many 

 different pigments but only so many grades and varieties of pigmen- 

 tation and depigmentation. The eye pigment, like that in the skin 

 and doubtless also in the hair, is there for protection, and though it 

 may not be strictly simple or homogeneous it behaves essentially as 

 one pigment which is distributed in small granules in the lining and 

 certain interstitial cells of the iris. The color of the iris is a reflec- 

 tion of light according to the quantity, density, and distribution of 

 the pigment granules. If these granules are in considerable quan- 

 tity and distributed throughout the endothelial, interstitial, and even 

 epithelial cells of the iris, the eye is brown to "black," the shade 

 differing with the total quantity and density of the granules. With 

 the maximum quantity the eye is black, as in some negroes; on the 

 other hand, as the quantity of the pigment decreases we have gradu- 

 ally a lighter and lighter shade of brown until this passes into light 

 brown, then grayish or greenish brown, then bluish or greenish 

 gray, and finally, when no pigment remains in either the anterior 

 lining or the interstitial cells of the iris, with but little in the endo- 

 thelium, the eye is blue. 



