The Making of Species 
the still earlier progenitors of these two species, 
we should probably see the adults dark-coloured. 
I infer that this would be the case, from the 
analogy of many other birds, which are dark 
whilst young, and when adult are white; and 
more especially from the adult of the Ardea 
gularis, the colours of which are the reverse 
of those of A. asha, for the young are dark- 
coloured and the adults white, the young having 
retained a former state of plumage. It appears, 
therefore, that the progenitors in their adult con- 
dition of the A. asha, the Buphus, and of some 
allies have undergone, during a long line of 
descent, the following changes of colour: firstly 
a dark shade, secondly pure white, and thirdly, 
owing to another change of fashion (if I may so 
express myself), their present slaty, reddish or 
golden-buff tints. These successive changes are 
intelligible only on the principle of novelty 
having been admired by the birds for the sake 
of novelty.” 
This reasoning may appear far-fetched and un- 
convincing. It seems, however, quite likely that 
the hen may select as her mate the suitor who 
is conspicuously different from the others, not 
because she admires novelty, but because his 
conspicuousness attracts her attention and en- 
ables her to make up her mind quickly to take 
him and thus rid herself of the other troublesome 
admirers, who are all very much alike. 
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