X COLOURS AND ORNAMENTS CHARACTERISTIC OF SEX 295 



as being due to the general laws of growth and derelop- 

 ment, and make it unnecessary to call to our aid so hypo- 

 thetical a cause as the cumulative action of female prefer- 

 ence. There remains, however, a general argument, arising 

 from the action of natural selection itself, which renders it 

 almost inconceivable that female preference could have been 

 effective in the way suggested; while the same argument 

 strongly supports the view here set forth. Natural selec- 

 tion, as Ave have seen in our earlier chajDters, acts per- 

 petually and on an enormous scale in weeding out the 

 "unfit" at every stage of existence, and preserving only 

 those which are in all respects the very best. Each year, only 

 a small percentage of young birds survive to take the place of 

 the old birds which die ; and the survivors will be those which 

 are best able to maintain existence from the egg onwards, an 

 important factor being that their parents should be well able 

 to feed and protect them, while they themselves must in turn 

 be equally able to feed and protect their own offspring. Now 

 this extremely rigid action of natural selection must render 

 any attempt to select mere ornament utterly nugatory, unless 

 the most ornamented always coincide with " the fittest " in 

 every other respect ; while, if they do so coincide, then any 

 selection of ornament is altogether superfluous. If the most 

 brightly coloured and fullest plumaged males are not the most 

 healthy and vigorous, have not the best instincts for the proper 

 construction and concealment of the nest, and for the care 

 and protection of the young, they are certainly not the fittest, 

 and Avill not survive, or be the parents of survivors. If, on 

 the other hand, there is generally this correlation — if, as has 

 been here argued, ornament is the natural product and direct 

 outcome of superabundant health and vigour, then no other 

 mode of selection is needed to account for the presence of 

 such ornament. The action of natural selection does not 

 indeed disprove the existence of female selection of ornament 

 as ornament, but it renders it entirely ineffective ; and as 

 the direct evidence for any such female selection is almost 

 nil, while the objections to it are certainly weighty, there can 

 be no longer any reason for upholding a theory which was 

 provisionally useful in calling attention to a most curious and 

 suggestive body of facts, but which is now no longer tenable. 



