Chap. XVI.] COLOR AND PROTECTION 213 



males at an early age not being then selected, on the con- 

 trary being often eliminated as dangerous, while similar 

 variations occurring at or near the period of reproduction 

 have been preserved, it follows that the plumage of the 

 young will often have been left unmodified, or but little 

 modified. "We thus get some insight into the coloring of 

 the progenitors of our existing species. In a vast number 

 of species, in five out of our six classes of cases, the adults 

 of one sex or both are brightly colored, at least during 

 the breeding-season, while the young are invariably less 

 brightly colored than the adults, or are quite dull-colored ; 

 for no instance is known, as far as I can discover, of the 

 young of dull-colored species displaying bright colors, or 

 of the young of brightly-colored species being more bril- 

 liantly colored than their parents. In the fourth class, 

 however, in which the young and the old resemble each 

 other, there are many species (though by no means all) 

 brightly-colored, and as these form whole groups we may 

 infer that their early progenitors were likewise brightly- 

 colored. With this exception, if we look to the birds of 

 the world, it appears that their beauty has been greatly 

 increased since that period, of which we have a partial 

 record in their immature plumage. 



On the Color of the Plumage in relation to Protection. 

 — It will have been seen that I cannot follow Mr. Wallace 

 in the belief that dull colors when confined to the females 

 have been in most cases specially gained for the sake of 

 protection. There can, however, be no doubt, as formerly 

 remarked, that both sexes of many birds have had their 

 colors modified for this purpose, so as to escape the notice 

 of their enemies ; or, in some instances, so as to approach 

 their prey unobserved, in the same .manner as owls have 

 had their plumage rendered soft, that their flight may not 

 be overheard. Mr. Wallace remarks 60 that " it is only in 



50 Westminster Review,' July, lSBY, p. 5. 



