€hap. XVIIL 
DEVELOPMENT OF HAIE. 
285 
the rams alone of the above-mentioned African breed of 
sheep, is a true secondary sexual character, for it is not 
developed, as I hear from Mr. Winwood Keade, if the 
animal be castrated. Although we ought to be ex- 
tremely cautious, as shewn in my work on ‘Variation 
under Domestication,’ in concluding that any character, 
even with animals kept by semi-civilised people, has 
not been subjected to selection by man, and thus aug- 
mented ; yet in the cases just specified this is im- 
probable, more especially as the characters are confined 
to the males, or are more strongly developed in them 
than in the females. If it were positively known that 
the African ram with a mane was descended from the 
same primitive stock with the other breeds of sheep, 
or the Berbura male-goat with his mane, dewlap, &c., 
from the same stock with other goats ; and if selec- 
tion has not been applied to these characters, then 
they must be due to simple variability, together with 
sexually-limited inheritance. 
In this case it would appear reasonable to ex- 
tend the same view to the many analogous characters 
occurring in animals under a state of nature. Never- 
theless I cannot persuade myself that this view is 
applicable in many cases, as in that of the extraordi- 
nary development of hair on the throat and fore-legs 
of the male Ammotragus, or of the immense beard of 
the male Pithecia. With those antelopes in which the 
male when adult is more strongly-coloured than the 
female, and with those monkeys in which this is like- 
wise the case, and in which the hair on the face is of a 
different colour from that on the rest of the head, being 
arranged in the most diversified and elegant manner, 
it seems probable that the crests and tufts of hair have 
on the practice of selection by semi- civilised people. For the Berbura 
goat, see Dr. Gray, ‘ Catalogue,’ ibid. p. 157. 
