Polygamy has existed and still exists among the Orientals; but owing to the limited number of women that are at a man’s disposal, and owing to the expense of their maintenance, it is at present practised only by the privileged and propertied classes. The counter-part of polygamy is polyandry. This is found especially among the mountaineers of Thibet, the Garras living at the boundary of India and China, the Baigas in Godwana, the Nairs in the southernmost part of India, and also among the Eskimos and Aleuts. Descent is determined on the mother’s side--as must needs be the case--and the children belong to her. The woman’s husbands usually are brothers. If an oldest brother marries, the other brothers thereby become husbands to his wife. But she has the right to take other husbands beside these. The men also are entitled to several wives. From what conditions polyandry sprang is as yet unexplained. As the tribes practising polyandry without exception live either in mountainous regions of a high altitude or in the frigid zone, polyandry may perhaps be explained by a phenomenon that Tarnowsky has pointed out.[22] Tarnowsky was told by reliable travelers that a lengthy sojourn on high altitudes greatly diminishes sexual desire, which reawakens with renewed vigor upon descending. This diminution of sexual desire, so Tarnowsky believes, might explain the slow increase in population in mountainous regions, and by becoming hereditary might be one of the symptoms of degeneration leading to perversity. Continuous living in high altitudes or in frigid zones might in the same manner signify that polyandry did not make extraordinary demands on women. Women themselves are influenced accordingly by their nature, since among Eskimo girls menstruation, as a rule, does not set in until the nineteenth year, while in the torrid zone it sets in with the ninth or tenth year, and in the temperate zone between the fourteenth and sixteenth year. It is generally known that hot countries have a stimulating effect upon sexual desire; that is why polygamy is especially prevalent in hot countries. In the same way cold lands, and high altitudes having a similar climate, may have a restrictive influence. It is also a matter of experience that conception is less frequent when a woman has cohabitation with several men. The increase in population is, therefore, weak where polyandry exists, and is adapted to the difficulty of obtaining food in cold climes and high altitudes. This goes to show that even in regard to this strange custom of polyandry, the relations of the sexes are in the last instance determined by the methods of production. It still remains to be investigated whether the frequent killing of female infants is practised among the tribes living in mountainous regions or in the frigid zone, as has been reported of Mongolian tribes living in the mountainous regions of China. [17] Backofen: “The Matriarchate.”