Page:The Zoologist, 4th series, vol 4 (1900).djvu/101

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Thus the largest hen, although a bigger bird than the largest cock, measures half an inch less in entire length of wing, this difference being due entirely to the lengthening of the second to the fifth primaries, with their coverts, in the male birds. These same feathers are often, though by no means invariably, narrower in the females than in the males, and when this is the case the resisting power of the wing must be considerably weakened.

The width of the wing from back to front shows little, if any, sexual difference, the secondaries being about of equal length in male and female; the natural effect of breadth without correspondingly developed length would be to produce a somewhat heavier and slower flight, so that in every respect the male bird has the advantage.