Chap. XIX. SEXUAL DIFFERENCES. 319 



cranium of the adult male presents a strongly-marked 

 sagittal crest, which is absent in the female ; and Ecker 

 found a trace of a similar difference between the two 

 sexes in the Australians.^ With monkeys when there 

 is any diff:^rence in the voice, that of the male is the 

 more powerful. We have seen that certain male mon- 

 keys, have a well-developed beard, wliicli is quite de- 

 ficient, or much less developed in the female. No in- 

 stance is known of the beard, whiskers, or moustache 

 being larger in a female than in the male monkey. 

 Even in the colour of the beard there is a curious 

 parallelism between man and tlie Quadrumana, for 

 when in man the beard differs in colour from the hair 

 of the head, as is often the case, it is, I believe, in- 

 variably of a lighter tint, being often reddish. I have 

 observed this fact in England, and Dr. Hooker, who 

 attended to this little point for me in Russia, found 

 no exception to the rule. In Calcutta, Mr. J. Scott, 

 of the Botanic G-ardens, was so kind as to observe with 

 care the many races of men to be seen there, as well 

 as in some other parts of India, namely, two races in 

 Sikhim, the Bhoteas, Hindoos, Burmese, and Chinese. 

 Although most of these races have very little hair on 

 the face, yet he always found that when there was any 

 difference in colour between the hair of the head and 

 the beard, the latter was invariably of a lighter tint. Now 

 with monkeys, as has already been stated, the beard 

 frequently differs in a striking manner in colour from 

 the hair of the head, and in such cases it is invariably 

 of a lighter hue, being often pure white, sometimes 

 yellow or reddish.^ 



8 ' Antliropological Review,' Oct. 18U8, p. 353. X(\CvV^ ^^ 



3 Mr. Blyth informs me that he lias never seen more than one instance'® ^i 



of the beard, whiskers, &c., in a monkey becoming wbite witli old age. ©-^j>. 



a 5 is so commonly the case with us. This, however, occurred in an a"-ed 



