. The bird, its form and function. Birds. 52 The Bird We have seen how birds, by moulting their feathers, change the colour of their plumage; in some cases several times each year. There is, however, still another way in which the appearance of new colour is brought about. Not by increase of pigment, for the feather when once full grown is dead; but by the mere breaking or fraying. Fig. 34.— Iht three moults of the Ptarmigan, shown in three indixiduals. (Courtesy of .American Museum.) of the edges of each feather. It is thus that the Snow- flake brushes off the rusty trimmings of his winter's
. The bird, its form and function. Birds. 52 The Bird We have seen how birds, by moulting their feathers, change the colour of their plumage; in some cases several times each year. There is, however, still another way in which the appearance of new colour is brought about. Not by increase of pigment, for the feather when once full grown is dead; but by the mere breaking or fraying. Fig. 34.— Iht three moults of the Ptarmigan, shown in three indixiduals. (Courtesy of .American Museum.) of the edges of each feather. It is thus that the Snow- flake brushes off the rusty trimmings of his winter's suit and returns to his home in the far North, dressed in spick- and-span black and white. A much more familiar exam- ple is to be seen at our very doorstep. The cock English Sparrow in midwinter is even more sombrelj^ clad than usual; but as spring approaches, although he can attain to no elaborate song or flowing j^lume, 3'et even this. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Beebe, William, 1877-1962. New York, Holt
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbirds, bookyear1906
