attention to this rudimentary covering, and has thrown much light on the subject. He showed that the female as well as the male foetus possessed this hairy covering, showing that both are descended from progenitors, both sexes of whom were hairy. Eschricht also showed, as stated above, that the hair on the face of the fifth month foetus is longer on the face than on the head, which indicates that our semi-human progenitors were not furnished with long tresses, which must therefore have been a late acquisition. The question naturally arises, is there any explanation for the loss of hair covering? [Illustration: FIG. I.--The Hairy-Faced Burmese Family. (From Scientific American, Feb. 20, 1875.)] Darwin is of the opinion that the absence of hair on the body is, to a certain extent, a secondary sexual character; for, in all parts of the world, women are less hairy than men. He says: "Therefore we may reasonably suspect that this character has been gained through sexual selection." As the body in woman is less hairy than in man, and as this character is common to all races, we may conclude that it was our female semi-human ancestors who were first divested of hair. Professor Grant Allen[34] has given much study to the subject of the loss of hair in the human being; and his investigations are worthy of careful consideration. He shows conclusively that those parts of an animal which are in constant contact with other objects are specially liable to lose their hair. This is noticeable on the under surface of the body of all animals which habitually lie on the stomach. The soles of the feet of all mammals where they touch the ground are quite hairless; the palms of the hands in the quadrumana present the same appearance. The knees of those species which frequently kneel, such as camels and other ruminants, are apt to become bare and hard-skinned. The friction of the water has been the means of removing the hair from many aquatic mammals--the whales, porpoises, dugongs, and manatees are examples.