192 SEXUAL SELECTION: BIRDS. [Pakt II. 



colored or more conspicuous than the males; and the 

 young, as far' as they are known, resemble the adult males 

 instead of the adult females. But the difference between 

 the sexes is never nearly so great as occurs with many 

 birds in the first class, and the cases are comparatively 

 rare. Mr. Wallace, who first called attention to the singu- 

 lar relation which exists between the less bright colors of 

 the males and their performing the duties of incubation, 

 lays great stress on this point, 13 as a crucial test that ob- 

 scure colors have been acquired for the sake of protection 

 during the period of nesting. A different view seems to 

 me more probable. As the cases are curious, and not 

 numerous, I will briefly give all that I have been able to 

 find. 



In one section of the genus Turnix, quail-like birds, the 

 female is invariably larger than the male (being nearly 

 cwice as large in one of the Australian species), and this is 

 an unusual circumstance with the Gallinacese. In most 

 of the species the female is more distinctly colored and 

 brighter than the male, 14 but in some few species the sexes 

 are alike. In Turnix taigoor of India the male " wants 

 the black on the throat and neck, and the whole tone of 

 the plumage is lighter and less pronounced than that of 

 the female." The female appears to be more vociferous, 

 and is certainly much more pugnacious, than the male ; 

 so that the females and not the males are often kept by 

 the natives for fighting, like game-cocks. As male birds 

 are exposed by the English bird-catchers for a decoy near 

 a trap, in order to catch other males by exciting their ri- 



13 ' Westminster Review, July, 186*7, and A. Murray,. ' Journal of 

 Travel,' 1868, p. 83. 



14 For the Australian species, see Gould's ' Hand-book,' etc., vol. ii 

 pp. 178, 180, 186, 188. In the British Museum specimens of the Aus- 

 tralian Plain-wanderer {Pedioncmxts iorqualus) may be seen, showing 

 similar sexual differences. 



