The plumage of the Wild Duck is dense and elastic. The head, throat, and upper part of the neck of the male are adorned with hues of a bright emerald green, shot with violet; its breast is of a purplish brown; its back is ashy brown, sprinkled with greyish-white zigzag bars; the four feathers in the middle of the tail, curling up at the end in a semicircle, are of a blackish hue with a green reflection; its length is about twenty-four inches; length of wing, thirty-five inches. The female, which is always smaller than her mate, does not possess the bright colours which adorn the Drake. Her plumage is brown and russet grey. Individuals sometimes, though seldom, vary. Sir William Jardine states that he has seen Drakes having the upper parts of a bluish grey, decreasing in depth of colouring down the breast; and Mr. Yarrell mentions two instances in which females of this species have assumed, to a considerable extent, the appearance and plumage of the Mallard, even to the curling feathers of the tail. On the other hand, the male plumage, according to Mr. Waterton, undergoes a singular alteration. About the end of May the breast and back of the Drake begin to change colour; in a few days the curled feathers of the tail drop out, and grey feathers begin to appear in the lovely green plumage round the eyes; and, by the 23rd of June, scarcely one green feather remains. By the 6th of July all the green feathers have disappeared, and the male has assumed the female garb, but darker in colour. In August this new plumage begins to drop off, and by the middle of October the Drake again reappears in all the rich magnificence of its former dress. The Wild Duck (Fig. 86) forms the original stock from which our Domestic Ducks have sprung. Their favourite resorts are to be found in those hyperborean regions whose rigorous climate renders it uninhabitable by man. The rivers of Lapland, Greenland, and Siberia are sometimes literally covered with them; and, in the month of May, their nests are there found in quantities which the imagination can scarcely picture. At the first approach of frost their earliest harbingers begin to appear among us, and about the middle of October these travelling bands arrive in increasing numbers.