26 THE DESCENT OP MAN. Part I. 



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 coinci- 

 dence, we must consider the woolly covering of the 

 foetus to be the ruclimental representative of the first 

 permanent coat of hair in those mammals which are 

 born hairy. This representation is much more com- 

 plete, in accordance with the usual law of embryological 

 development, than that afforded by the straggling hairs 

 on the body of the adult. 



It appears as if the posterior molar or wisdom-teeth 

 were tending to become rudimentary in the more civi- 

 lised 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 dentists. They are also much more 

 liable to vary both in structure and in the period of 

 their development than the other teeth. 31 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. 32 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, 33 and this 

 shortening may, 1 presume, be safely attributed to civi- 



S1 Dr. Webb, ' Teeth in Man and the Anthropoid Apes,' as quoted by 

 Dr. C. Carter Blake in ' Anthropological Keview,' July, 1867, p. 299. 



32 Owen, ' Anatomy of Vertebrates,' vol. iii. pp. 320, 321, and 325. 



33 ' On the Primitive Form of the Skull,' Eng. translat. in ' Anthro- 

 pological Keview,' Oct. 1868, p. 426. 



