RUDIMENTS. 19 



scattered hairs of considerable length rising from the naked skin 

 above the eyes, and corresponding to our eyebrows; similar long 

 hairs project from the hairy covering of the superciliary ridges in 

 some baboons. 



The fine wool-like hair, or so-called lanugo, with which the 

 human foetus during the sixth month is thickly covered, offers a 

 more curious case. It is first developed, during the fifth month, 

 on the eyebrows and face, and especially round the mouth, where 

 it is much longer than that on the head. A mustache of this 

 kind was observed by Eschricht" on a female foetus; but this is 

 not so surprising a circumstance as it may first appear, for the 

 two sexes generally resemble each other in all external characlero 

 during an early period of growth. The direction and arrange- 

 ment of the hairs on all parts of the fcetal body are the same 

 as in the adult, but are subject to much variability. The whole 

 surface, including even the forehead and ears, is thus thickly 

 clothed; but it is a significant fact that the palms of the hands 

 and the soles of the feet are quite 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." Prof. Alex. Brandt informs me that he has com- 

 pared the hair from the face of a man thus characterized, 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 con- 

 tinued 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 tend- 

 ing to become rudimentary in the more civilized races of man. 

 These teeth are rather smaller than the other molars, as is like- 

 wise 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 



•"> Eschricht, ibid. s. 40, 47. 



"■ See my 'Variation of Animals and Plants under Domestication,' vol. 

 li. 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. 



