naked, like the inferior surfaces of all four extremities in most of
the lower animals. As this can hardly be an accidental coincidence, the
woolly covering of the foetus probably represents the first permanent
coat of hair in those mammals which are born hairy. Three or four cases
have been recorded of persons born with their whole bodies and faces
thickly covered with fine long hairs; and this strange condition is
strongly inherited, and is correlated with an abnormal condition of the
teeth. (41. See my Variation of Animals and Plants under
Domestication, vol. ii. p. 327. Prof. Alex. Brandt has recently sent
me an additional case of a father and son, born in Russia, with these
peculiarities. I have received drawings of both from Paris.) Prof.
Alex. Brandt informs me that he has compared the hair from the face of
a man thus characterised, aged thirty-five, with the lanugo of a
foetus, and finds it quite similar in texture; therefore, as he
remarks, the case may be attributed to an arrest of development in the
hair, together with its continued growth. Many delicate children, as I
have been assured by a surgeon to a hospital for children, have their
backs covered by rather long silky hairs; and such cases probably come
under the same head.
It appears as if the posterior molar or wisdom-teeth were tending to
become rudimentary in the more civilised races of man. These teeth are
rather smaller than the other molars, as is likewise the case with the
corresponding teeth in the chimpanzee and orang; and they have only two
separate fangs. They do not cut through the gums till about the
seventeenth year, and I have been assured that they are much more
liable to decay, and are earlier lost than the other teeth; but this is
denied by some eminent dentists. They are also much more liable to
vary, both in structure and in the period of their development, than
the other teeth. (42. Dr. Webb, Teeth in Man and the Anthropoid Apes,
as quoted by Dr. C. Carter Blake in Anthropological Review, July 1867,
p. 299.) In the Melanian races, on the other hand, the wisdom-teeth are
usually furnished with three separate fangs, and are generally sound;
they also differ from the other molars in size, less than in the
Caucasian races. (43. Owen, Anatomy of Vertebrates, vol. iii. pp.
320, 321, and 325.) Prof. Schaaffhausen accounts for this difference
between the races by the posterior dental portion of the jaw being
always shortened in those that are civilised (44. On the Primitive
Form of the Skull, Eng. translat., in Anthropological Review, Oct.
1868, p. 426), and this shortening may, I presume, be attributed to
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