Page:Popular Science Monthly Volume 17.djvu/18

8 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 meteorological data bearing on their case.

The climate and complexions of the rainless coast of Peru correspond very closely to those of the rainless valley of Egypt, the Peruvians 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 Fé, 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 Stanley, 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 Schweinfurth, 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