500 THE DESCENT OF MAN 



and how harmoniously they are combined. The colors are 

 often metallic and iridescent. Circular spots are eometimea 

 surrounded by one or more differently shaded zones, and ars 

 thus converted into ocelli. Nor need much be said on the 

 wonderful difference between the sexes of many birds. The 

 common peacock offers a striking instance. Female birds 

 of paradise are obscurely colored and destitute of all orna- 

 ments, while the males are probably the most highly deco- 

 rated of all birds, and in so many different ways, that they 

 must be seen to be appreciated. The elongated and goldea 

 orange plumes which spring from beneath the wings of the 

 Paradisea apoda, when vertically erected and made to vi- 

 brate, are described as forming a sort of halo, in the centre 

 of which the head "looks like a little emerald sun with its 

 rays formed by the two plumes. " " In another most beau- 

 tiful species the head is bald, "and of a rich cobalt blue, 

 crossed by several lines of black velvety feathers." " 



Male humming-birds (Figs. 48 and 49) almost vie with 

 birds of paradise in their beauty, as every one will admit 

 who has seen Mr. Gould's splendid volumes, or his rich 

 collection. It is very remarkable in how many different 

 ways these birds are ornamented. Almost every part of 

 their plumage has been taken advantage of, and modified; 

 and the modifications have been carried, as Mr. Gould 

 showed me, to a wonderful extreme in some species be- 

 longing to nearly every sub-group. Such cases are curi- 

 ously like those which we see in our fancy breeds, reared 

 by man for the sake of ornament: certain individuals orig- 

 inally varied in one character, and other individuals of the 

 same species in other characters; and these have been seized 

 on by man and much augmented — as shown by the tail of 

 the fan-tail pigeon, the hood of the jacobin, the beak and 

 wattle of the carrier, and so forth. The sole difference be- 



™ Quoted from M. de tafresnaye, in "Annals and Magazine of Natural His- 

 tory," vol. xiii., 1854, p. 157; see also Mr. Wallace's much fuller account in 

 VoX. IX., 1857, p. 412, and in hia "Malay Archipelago." 



■" Wallace, "The Malay Archipelago," vol. ii., 1869, p. 405. 



