78 SEXUAL selection: birds. PartIL 



orange yjlumes whicli spring from beneath tlie wings 

 of tlie Paradisea apoda (see fig. 47 of P. rubra, a much 

 less beautiful species), when vertically erected and made 

 to vibrate, 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 beautiful species the head is bald, 

 " and of a rich cobalt blue, crossed by several lines of 

 " black velvetv 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 the plumage has been taken advantage of and 

 modified ; and the modifications have been carried, as 

 Mr. Gould shewed me, to a wonderful extreme in some 

 sj^ecies belonging to nearly every sub-group. Such cases 

 are curiously like those which we see in our fancy 

 breeds, reared by man for the sake of ornament : certain 

 individuals originally varied in one character, and other 

 individuals belonging to the same species in other 

 characters ; and these have been seized on bv man and 

 augmented to an extreme point — as the tail of the 

 fantail-pigeon, the hood of the jacobin, the beak and 

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

 between these cases is that in the one the result is due 

 to man's selection, whilst in the other, as with Hum- 

 ming-birds, Birds of Paradise, &c., it is due to sexual 

 selection, — that is to the selection by the females of the 

 more beautiful males. 



^^ Quoted from M. de Lafresnaye, in ' Annals and Mag. of Nat. 

 Hist.' vol. xiii. 1854. p. 157 : see also Mr. Wallace's much fuller ac- 

 count in voL XX. 1857, p. 412, and in his Mahiy Archipehigo. 



C9 Wallace, ' The Malay Archipelago,' vol. ii. 1869, p. 405. 



