30ft THE DESCENT OF MAN. 



The males of various members of the ox family (Bovidae), 

 and of certain antelopes, are furnished with a dewlap or 

 great fold of skin on the neck, which is much less devel- 

 oped in the female. 



Now, what must we conclude with respect to such sexual 

 differences as these? No one will pretend that the beards 

 of certain male goats, or the dewlap of the bull, or the 

 crests of hair along the backs of certain male antelopes, 

 are of any use to them in their ordinary habits. It is pos- 

 sible that the immense beard of the male Pithecia, and the 

 large beard of the male orang, may protect their throats 

 when fighting ; for the keepers in the Zoological Gardens 

 inform me that many monkeys attack each other by the 

 throat; but it is not probable that the beard has been 

 developed for a distinct purpose from that served by the 

 whiskers, mustache and other tufts of hair on the face; 

 and no one will suppose that these are useful as a protec- 

 tion. Must we attribute all these appendages of hair or 

 skin to mere purposeless variability in the male? It cannot 

 be denied that this is possible; for in many domesticated 

 quadrupeds certain characters, apparently not derived 

 through reversion from any wild parent form, are confined 

 to the males, or are more developed in them than in 

 females; for instance, the hump on the male zebu-cattle of 

 India, the tail of fat-tailed rams, the arched outline of the 

 forehead in the males of several breeds of sheep, and, 

 lastly, the mane, the long hairs on the hind legs, and the 

 dewlap of the male of the Berbura goat.* The mane, 

 which occurs only in the rams of an African breed of 

 sheep, is a true secondary sexual character, for, as I hear 

 from Mr. Winwood Heade, it is not developed if the animal 

 be castrated. Although we ought to be extremely cautious, 

 as shown in my work on " Variation under Domestication/' 

 in concluding that any character, even with animals kept 

 by semi-civilized people, has not been subjected to selec- 

 tion by man, and thus Augmented, yet in the cases just 

 specified this is improbable; moro especially as the charac- 

 ters are confined to the males, or are more strongly devel- 

 oped in them than in the females. If it were positively 



* See the chapters on these several animals in vol. i, of ray 

 " Variation of. Animals under Domestication;" also vol. ii, p. 73; also 

 chap, xx, on the practice of selection by semi-civilized people. For 

 the Berbura goat, see Dr. Gray, " Catalogue," ibid, p. 157. 



