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 difference in the voice, that of the male is the 
more powerful. We have seen that certain male mon- 
keys, have a well-developed beard, which 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 the 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 Eussia, 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.^ 
/ 
^ ‘Anthropological Review/ Oct. 1868, p. 353. 
^ Mr. Blyth informs me that he has never seen more than one instance 
of the beard, whiskers, &c., in a monkey becoming white with old age, 
as is so commonly the case with ns. This, however, occurred in an aged 
