8 THE POPULAR SCIENCE MONTHLY. 



his dermis and epidermis are thicker. I believe that these facts supply 

 the explanation of the extreme unhealthiness of the African climate 

 for the white man. His thin outer skin permits his system to be 

 weakened by an undue loss of its fluids in the daytime and of its 

 heat at night, and in this condition he falls an easy prey to some 

 disease. 



There are black men in Africa, India, and Australia, because these 

 countries all have climates with long pronounced dry seasons. Owing 

 to the peculiar formation of the continent of America, its tropical 

 regions are more humid, and consequently no very dark natives are 

 found there. Of the great Papuan race, which inhabits New Guinea 

 and many smaller islands in that part of the Pacific, some branches are 

 black and some brown ; but I have not been able to procure meteoro- 

 logical data bearing on their case. 



The climate and complexions of the rainless coast of Peru corre- 

 spond very closely to those of the rainless valley of Egypt, the Peru- 

 vians being perhaps a shade darker. The dry climate of the tropical 

 part of the Andes has even affected the color of the Spanish Creoles ; 

 while in Cartagena and Guayaquil, towns with a humid climate on 

 the seacoast of South America, their complexion is as light as that of 

 native Spaniards, and fair hair still occurs, in Santa Fe, which is in the 

 mountain country, only dark complexions with dark hair are found. 

 Tschudi, indeed, asserts that the colder the climate (i. e., the greater 

 the elevation), the darker the color in Peru. 



Some of the evidence tending to show the connection of humidity 

 and fairness in Africa is quite striking. In the mountainous region of 

 Gambaragara, near the Albert Nyanza there lives, according to Stan- 

 ley, a race whose fairness so struck him that he supposes that it must 

 have come from the north. According to Lefebvre, the skin of the 

 Abyssinians becomes lighter during the rainy season. The Bongo, 

 Niam-Niam, and Monbuttoo tribes, whose fairness amazed Schwein- 

 furth, inhabit a wooded and presumably a humid country, while the 

 black Shillooks, with whom he contrasts them, dwell in a country 

 adapted to pastoral purposes, and therefore probably dry. In the 

 rainy regions of the Atlas Mountains there are said to be tribes 

 among whom many individuals with blue eyes, fair skin, and red 

 beard occur. 



Similar phenomena recur in Asia. The blonde races of the Caucasus 

 are found on its moist southern slope. The races on the dry northern 

 declivity have a Tartar complexion. The moistest part of India is the 

 jungle-covered southern slope of the Himalaya Mountains, and in this 

 quarter, accordingly, we hear of white races. The Rohillas, an Aryan 

 people, living northeast of Delhi, and the Lepchas, a Mongolian tribe, 

 near Darjeeling, may be mentioned as examples. In the north of 

 China proper there is a low-lying, swampy, and presumably somewhat 

 moist peninsula called Shantung. There is some evidence tending to 



