4^0 The Descent of Man. Part II. 



in the female as in the male ; though in not a few cases they are 

 rather larger in the male. When the male is furnished with 

 leg-spurs the female almost always exhibits rudiments of them^ 

 — the rudiment sometimes consisting of a mere scale, as in 

 Gallus. Hence it might be argued that the females had abori- 

 ginally been furnished with well-developed spurs, but that these 

 had subsequently been lost through disuse or natural selection. 

 But if this view be admitted, it would have to be extended to 

 innumerable other cases; and it implies that the female pro- 

 genitors of the existing spur-bearing species were once encum- 

 bered with an injurious appendage. 



In some few genera and species, as in Galloperdix, Acomus, 

 and the Javan peacock (Pavo rnuticus), the females, as w T ell as 

 the males, possess well-developed leg-spurs. Are we to infer from 

 this fact, that they construct a different sort of nest from that 

 made by their nearest allies, and not liable to be injured by their 

 spurs ; so that the spurs have not been removed. Or are we to 

 suppose that the females of these several species especially require 

 spurs for their defence ? It is a more probable conclusion that 

 both the presence and absence of spurs in the females result 

 from different laws of inheritance having prevailed, indepen- 

 dently of natural selection. With the many females in which 

 spurs appear as rudiments, we may conclude that some few of 

 the successive variations, through which they were developed in 

 the males, occurred very early in life, and were consequently 

 transferred to the females. In the other and much rarer cases, 

 in which the females possess fully develojDed spurs, we may 

 conclude that all the successive variations were transferred to 

 them; and that they gradually acquired and inherited the habit 

 of not disturbing their nests. 



The vocal organs and the feathers variously-modified for pro- 

 ducing sound, as well as the proper instincts for using them, 

 often differ in the two sexes, but are sometimes the same in both. 

 Can such differences be accounted for by the males having 

 acquired these organs and instincts, whilst the females have 

 been saved from inheriting them, on account of the danger to 

 which they would have been exposed by attracting the attention 

 of birds or beasts of prey ? This does not seem to me probable, 

 when we think of the multitude of birds which with impunity 

 gladden the country with their voices during the spring. 7 It is 



7 Daines Barrington, however, cubation. He adds, that a similar 



thought it probable ('Phil. Transact.' view may possibly account for the 



1773, p. 164) that few female birds inferiority of the female to the 



sing, because the talent would have male in plumage. 

 been dangerous to them duritg in- 



