CiiAP. XVI. COLOUR AND PROTECTION. 223 



of the young of brightly-coloured species being more 

 briUiantly coloured 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-coloured, and as these form whole groups, 

 we may infer that their early progenitors were likewise 

 brightly-coloured. With this exception, if we look to 

 the birds of the world, it appears that their beauty 

 lias been greatly increased since that period, of which 

 we have a partial record in their immature plumage. 



On the Colour of the Plumage m relation to Pro- 

 tection. — It will have been seen that I cannot follow 

 Mr. Wallace in the belief that dull colours when con- 

 fined 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 colours modified for this 

 purpose, so as to escape the notice of their enemies ; or, 

 in some instances, so as to approach their i^rey unob- 

 served, in the same manner as owls have had their 

 phmaage rendered soft, that their flight may not be 

 overheard. Mr. Wallace remarks ^° that "it is only 

 " in the tropics, among forests which never lose their 

 ^' foliage, that we find whole groups of birds, whose 

 " chief colour is green." It will be admitted by every 

 one, who has ever tried, how difficult it is to distinguish 

 parrots in a leaf-covered tree. Nevertheless, we must re- 

 member that many parrots are ornamented with crimson, 

 blue, and orange tints, which can hardly be protective. 

 Woodpeckers are eminently arboreal, but, besides green 

 species, there are many black, and black-and-white 

 kinds — all the species being apparently exposed to 



50 ' Westminster Review,' July, 1867, p. 5. 



