president’s address. 
123 
The females of these three species resemble each other so closely 
that it requires an expert to distinguish them. The males also 
resemble each other in having more or less olive-green heads and 
necks, but here the resemblance absolutely ceases. Chryscena 
victor and Chryscena luteovirens resemble each other in the 
structure of their feathers, which are much disintegrated, but the 
colour of the latter species, like that of the females of all three of 
them, is as green as the greenest grass, whilst that of the former is 
as vermilion as the ripest Seville orange. But this is not all the 
difference. In the male of Chryscena luteovirens the structure of 
the feathers is quite different from that of the other two species, 
or from that of its own female. The feathers are compact, not 
disintegrated, they are narrow, like the feathers on the throat of a 
Raven, and strange to say, those on the mantle and breast are 
bifid at the ends. The genus was originally established upon this 
character, by Eeichenbach and Bonaparte, in the dark ages of 
ornithology, when structure was allowed to ride rough-shod over 
colour as a foundation for a genus. ISow I suppose that no one 
would be rash enough to deny that these three birds are more 
nearly related to each other than they are to any other Pigeon, in 
spite of the abnormal structure of the feathers of the male of one 
of them. In all three species the immature males resemble the 
females both in colour and structure, so that we may fairly assume 
that the common ancestors of the three species were green birds 
with normally constructed feathers. 
Darwin would doubtless have attributed the brilliancy of the 
males’ attire to the accumulated results of many generations of 
sexual selection, aided possibly by the direct influence of some 
peculiar favourite food, whilst the uniformity of the females 
might be ascribed to the necessity of being as little conspicuous 
as possible whilst engaged in the duties of incubation. The new 
theory of Wallace, that it is an advantage to nearly allied species 
to differ in colour in order easily to recognise a stranger or a 
friend, completely breaks down on islands where each species is 
isolated from its near allies, and nevor comes into contact with 
them. 
