78 
SEXUAL SELECTION: BIKDS. 
Paet IL 
orange plumes which spring from beneath the wings 
of the 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 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 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 
species 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 by 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 Malay Archipelago, 
Wallace, ‘The Malay Archipelago,’ vol. ii. 1869, p. 405. 
