282 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1953 



Taking up Gloger's rule, first, we find that it was originally form- 

 ulated to account for the color of feathers and fur, rather than skin. 

 Birds and beasts of humid forested regions, in the cooler latitudes 

 as well as in the Tropics, tend to adopt sombre colors ; the association 

 is with humidity and shade, rather than with temperature. Since 

 individual birds and animals have been seen to grow darker or 

 lighter when carried from one environment to another, it is clear 

 that whatever influence produces this effect reflects a genetic capacity 

 of considerable latitude. At any rate, it does not apply to man. 

 His color variation is primarily concerned with the skin, which in 

 a precultural state must have been wholly, except for the scalp, 

 exposed to the elements, as in some racial and cultural situations 

 it still is. 



Speaking very broadly, human beings have three kinds of skin. 

 One is the pinkish-white variety that burns badly on exposure to 

 the sun and fails to tan. Such skin is found in a minority of indi- 

 viduals in the cloudy region of northwest Europe, among descendants 

 of the inhabitants of this area who have migi'ated elsewhere, and 

 among albinos anywhere. It is quite clearly defective skin, and 

 causes its owners trouble anywhere anytime they step out of the 

 shade. Clothing, lotions, wide-brimmed hats, and sun glasses help 

 to mitigate its deficiency. Luckily for the rest, relatively few of 

 mankind possess it. 



At the opposite extreme is black or chocolate-brown skin, familiar 

 as the integumental garb of the full-blooded Negro. Persons who 

 wear skin of this type are the same color all over, except for their 

 palms and soles. As I discovered in Ethiopia, the unexposed skin is 

 sometimes even darker than the portions exposed to the sun such as 

 the hands and face, perhaps owing to an increased thickening of the 

 horny layer in contact with solar radiations. Once this layer has 

 thickened, man with this kind of skin can travel anywhere without fear 

 of the sun ; he can roll up his sleeves, toss off his shirt, or run naked in 

 any climate where he or any other human would not be hindered by 

 the cold. Negroes have gone to Alaska and to the North Pole. 



In between is the range of integumental color possessed by the ma- 

 jority of mankind, belonging to skins which, although appearing as 

 white, olive, yellowish, reddish, or brown, have one feature in com- 

 mon. The skin that is covered by clothing, if any, is relatively light. 

 Exposed areas, if the light is strong enough, tan. In some populations 

 this tanning can approach the darkness of the black-skinned peoples. 

 However, skin that can tan can also bleach. Peoples who live in mid- 

 latitude regions where the air is dry and the sky cloudless in summer, 

 while in winter dampness and clouds are the rule, can shift their skin 

 color with the seasons. This capacity for developing pigment in re- 



