198 SEXUAL SELECTION: BIRDS. Part IL 



tints of both sexes of many birds bad been acquired and 

 preserved for the sake of protection,— for example, of 

 the hedge-warbler or kitty- wren (Accentor modular is and 

 Troglodytes vulgaris), with respect to which we have no 

 sufficient evidence of the action of sexual selection. 

 We ought, however, to be cautious in concluding that 

 colours which appear to us dull, are not attractive to the 

 females of certain species ; we should bear in mind such 

 cases as that of the common house-sparrow, in which 

 the male differs much from the female, but does not 

 exhibit any bright tints. No one probably will dispute 

 that many gallinaceous birds which live on the open 

 ground have acquired their present colours, at least in 

 part, for the sake of protection. We know how well they 

 are thus concealed ; we know that ptarmigans, whilst 

 changing from their winter to their summer plumage, 

 both of which are protective, suffer greatly from birds 

 of prey. But can Ave believe that the very slight dif- 

 ferences in tints and markings between, for instance, 

 the female black and red-grouse serve as a protection ? 

 Are partridges, as they are now coloured, better pro- 

 tected than if they had resembled quails ? Do the 

 slight differences between the females of the common 

 pheasant, the Japan and golden pheasants, serve as a 

 protection, or might not their plumages have been 

 interchanged with impunity? From what Mr. Wal- 

 lace has observed of the habits of certain gallinaceous 

 birds in the East he thinks that such slight differences 

 are beneficial. For myself, I will only say that I am 

 not convinced. 



Formerly when I was inclined to lay much stress on 

 the principle of ]3rotection, as accounting for the less 

 bright colours of female birds, it occurred to me that 

 possibly both sexes and the young might aboriginally 

 have been brightly coloured in an equal degree ; but 



