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Mr. Frank Finn,



the female is noticably the duller of the two ; in the Turkey, the

cock only has well-developed structural decorations, and is also

far larger than the hen ; and many birds have a plumage which

can hardly be called rich, but yet shows a distinction between

the sexes, or between both sexes and duller allies ; for instance,

the cock Sparrow (Passer domesticus ) is not a richly coloured

bird, but masculinely bright in comparison to the hen, as are

both sexes of the Tree-Sparrow ( P . montanus ) compared to many

finches, such as the Rock-Sparrows ( Petronia ) ; but on the whole

the classes are pretty definite.


Sometimes several differences will be found between near

allies; this is particularly well shown in the duck family, e.g. all

the nearest allies of our common wild duck ( Anas boschas ) have

plumage, in both sexes, much like the female of that bird ; but

in the three kinds of Wigeon ( Mareca) we get one with both sexes

of a masculine type (the Chilian), while the other two have bright

males and dull females. Similarity of general habits, then, has

nothing to do with sex-colouration ; nor does this similarity

affect the question of the superiority of the male over the female

sex or vice versa, since the Ffemipodes and Tinamous, in which

the female is the finer bird, agree in general habits most closely

with quails and partridges, in which many kinds have superior

males.


We may now pass to the question of display, and in regard

to this the following facts seem to be well established :—


I. Most (probably all) birds display in some way or other,

whether dull or blight, specially decorated or not. Profi

A. R. Wallace has emphasized (Darwinism) the display

of dull-coloured birds, e.g. goatsuckers, geese and vul¬

tures ; Mr. Howard (British Warblers) has shown that

warblers do it ; Mons. G. Rogeron (Les Canards) has

pointed it out in the case of the dull-coloured allies

of the Mallard. The display of bright-coloured and

decorated birds needs no comment; everybody knows

it, whether aviculturist or not !


As Darwin says, all individuals of a species display in the

same way ; it may also be pointed out that nearly allied

species do so, whether bright or dull, as in the case of



II.



