Chap. XV.] COLOR AXD XIDIFICATIOX. 163 



aquaticus) builds a domed nest, and the sexes differ about 

 as much as in the case of the rinsr-ouzel. The black and 

 red grouse (Tetrao tetrix and T. Scoticus) build open 

 nests, in equally well-concealed spots, but in the one spe- 

 cies the sexes differ greatly, and in the other very little. 



Notwithstanding the foregoing objections, I cannot 

 doubt, after reading Mr. Wallace's excellent essay, that, 

 looking to the birds of the world, a large majority of the 

 species in which the females are conspicuously colored 

 (and in this case the males with rare exceptions are equal- 

 ly conspicuous) build concealed nests for the sake of pro- 

 tection. Mr. Wallace enumerates 18 a long series of groups 

 in which this rule holds good ; but it will suffice here to 

 give, as instances, the more familiar groups of kingfishers, 

 toucans, trogons, puff-birds (Capitonidce), plantain-eaters 

 (Musophagae), woodpeckers, and parrots. Mr. Wallace 

 believes that in these groups, as the males gradually ac- 

 quired through sexual selection their brilliant colors, these 

 were transferred to the females and were not eliminated 

 by natural selection, owing to the protection which they 

 already enjoyed from their manner of nidification. Ac- 

 cording to this view, their present manner of nesting was 

 acquired before their present colors. But it seems to me 

 much more probable that, in most cases, as the females 

 were gradually rendered more and more brilliant from 

 partaking of the colors of the male, they were gradually 

 led to change their instincts (sivpposing that they origi- 

 nally built open nests), and to seek protection by building 

 domed or concealed nests. No one, who studies, for in- 

 stance, Audubon's account of the differences in the nests 

 of the same species in the Northern and Southern United 

 States, 19 will feel any great difficulty in admitting that 

 birds, either by a change (in the strict sense of the word) 



* 8 4 Journal of Travel,' edited by A. Murray, vol. i. p. ^8. 



19 See many statements in the ' Ornithological Biography.' See, also, 



