PIGMENTATION IN OLD AMERICANS — HRDLICKA. 



455 



on, a very perceptibly higher grade of lightness than that of the fully 

 adult of the same class. In some persons the darkening of the hair 

 seems to progress until the time when the first traces of graying (in 

 individual hairs) commences. This progressive darkening of the hair 

 has been observed in all white people with hair lighter than black. Its 

 causes are not yet well understood. It means, of course, a progres- 

 sively greater production of the hair pigment, but whether this is due 

 to environmental stimuli, metabolic changes, or phylogenetic influ- 

 ence, is not as yet determined. There are decided individual varia- 

 tions in this respect, and possibly also sexual, locality, and other 

 differences. The whole subject deserves a separate, deep-going in- 

 vestigation. 



Our records on the distribution of hair color among the Old 

 Americans, as finally tabulated, are as follows : 



Old Americans: Color of hair. 



Males (1,009).. 

 Females (914). 



Lights 

 proper. 



Per cent. 

 5.3 

 6.9 



Light 



brown (not 



blond). 



Per cent. 

 16 

 14.2 



Medium 

 (medium 

 brown). 



Per cent. 

 50 

 42.9 



Darks 

 (dark, dark 

 brown , near 



black). 



Per cent. 

 25 

 29.8 



Black. 



Per cent. 

 1.1 

 1.3 



Reds. 



Per cent. 

 2.6 

 4.9 



These figures are striking in more than one respect. Over three- 

 fourths of the adult Old Americans have hair ranging from medium 

 to dark and black, while but one in 14.5 among the females and one 

 in near 16 among the males is in hair truly blond. The females, as 

 contrasted with the males, show a few more blonds and more reds, 

 but also more darks, while the males give a predominance of the 

 lighter and medium shades of brown. The females show the greater 

 diversity. 



An even closer insight into the conditions is, however, possible. 

 The following data give us the more detailed colors : 



• It goes without saying that, all possible care was exercised not to include any cases 

 of hair changed artificially. Fortunately this is not frequent in this class of people, 

 except perhaps among some of the older persons where the object is to mask grayness 

 and simulate the natural shade. 



