580 THE DESCENT OF MAN 



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 aboriginally been furnished with well-de- 

 veloped spurs, but that these had subsequently been lost 

 through disuse or natural selection. But if this view bo 

 admitted, it would have to be extended to innumerable 

 other cases; and it implies that the female progenitors of 

 the existing spur-bearing species were once encumbered 

 with an injurious appendage. 



In some few genera and species, as in Galloperdix, Aco- 

 mus, and the Javan peacock {Pavo muticus), the females, as 

 well 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 beea 

 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, independently 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 developed 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 

 producing 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, while 

 the females have been saved from inheriting them, on ac- 



