6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



writers it has been recognized to be, like the beard, a secondary sexual 

 character/ but, so far as I am aware, no one has hitherto shown that 

 it follows the lines laid down by the patternings of other primates. 

 The uniform raising of the forehead line can be found as a specific 

 character in the bald chimpanzee ; it is exactly paralleled by the pattern 

 of short and long hairs on the head of one South American monkey. 

 Pithecia monachns (pi. 3, fig. 2), and by the color pattern of another, 

 Cebus hypoleucus (pi. 3, fig. 3). The development of the two blunt 

 wedges results in a pattern much like the one present in the Celebean 

 black ape, Cynopithecus niger (pi. 3, fig. 5). The bald spot on top 

 of the crown is an occasional character of the toque macaque, 

 Macaca pileata (pi. 3, fig. 7). The completely developed human 

 bald area (pi. 3, fig. 8) is perfectly outlined in the South American 

 monkey known as Cacajao ruhicimdus (pi. 3, figs. 9 and 10). The 

 long dark hair at the side and back of the head of this animal occupies 

 the area that remains haired in normal human baldness, while the 

 light hair on the median area corresponding with the human bald spot 

 is so short and sparse that it does not conceal the skin of the scalp 

 in the living animal (two have recently been on exhibition in the 

 National Zoological Park). Finally it is to be noticed that the human 

 bald area follows the outline of the dark cap of the West African 

 gorilla (pi. 5, fig. 5) as well as that of a color pattern not infre- 

 quently seen in blond men. This pattern, (which appears to occur 

 in women also, but is obscured by long hair) is produced by an 

 obviously paler tint of the hair that grows on the bald-spot area. 

 It is visible as a faint but accurate picture of the color pattern made 

 by a bare scalp contrasted with dark side hair. At the Harvard com- 

 mencement exercises of 1930 I saw it on the heads of seven of the 

 young men awaiting the conferring of their degrees. 



TURNING GRAY 



Another change in the human hair that begins at or slightly after 

 the attainment of full maturity is seen in the familiar process of turn- 

 ing gray ; this may lead in the end to a stage when all the pigmented 

 hairs of the entire body have been replaced by colorless ones. 



This loss of color, like baldness, has given rise to conjecture with- 

 out end. And, as in the case of baldness, its near relation to primate 

 patterning seems to have passed unnoticed. Nevertheless, it can be 



* Tlie examination of many liundreds of photographs makes it appear prob- 

 able that the males of races with strong beards tend to show the highest per- 

 centage of baldness, thus differentiating themselves most fully from the females. 



