PIGMENTATION IN OLD AMERICANS — HIIDLICKA. 



479 



in appearance and progress of graying there is great individual 

 variation. 



Some further light on the condition may be had by arranging the 

 data by age : 



Old Americans : Grayness of hair in relation to age. 



MALES. 



Age and number of subjects. 



24-30 (100). 

 31-40(63).. 

 41-50(44).. 

 51-60(35).. 

 61-05(8)... 



Total (250). 



None. 



74 



44.4 

 9.1 

 2.9 



42. S 



Very few 

 to few. 



Some to 

 one-third. 



18 

 27 



20.4 

 8.6 



18.8 



About 

 one-half 



(two- 

 fifths to 



four- 

 sevenths). 



6 



19.0 

 27.3 



8.5 



13.2 



1 



3.2 



11.4 



8.6 



Two- 

 thirds 

 to near 

 all. 



4.4 



1 



6.4 

 27.3 

 51.4 

 75.0 



16.4 



All. 



4.5 



20.0 

 25.0 



4.4 



FEMALES. 



Thirty per cent approximately of the Old American men and 11 

 per cent of the women have a few to over one-third of gray hair 

 before they pass their thirtieth year. Between 31 and 40 less than 

 half of the males and a little less than three-fifths of the females 

 are without gray hair, and the proportion of such persons is reduced 

 to a little over 10 per cent during the next decennium. Over 35 per 

 cent of the males between 41 and 50 and 16 per cent of the females 

 between these ages show already grayness that involves from two- 

 thirds to all the hair; and for those between 51 and 60 this propor- 

 tion rises to very nearly three-fourths of the males and seven-tenths 

 of the females. 



The females show throughout slightly less tendency to graying 

 than the males. Undue predominance of the two-thirds to nearly 

 all gray is shown again. 



Some day, when we shall have equally detailed data on graying 

 in other peoples, the above figures ought to make interesting com- 

 parison and lead to some definite deductions of anthropological 

 nature. 



