apart, and remains in hiding until his new plumage has grown, and with renewed health his social instincts are restored. It is only in the case of the male duck that this change from health and strength to sickness and impotence falls in the midst of the breeding season. [Illustration: MALLARDS. PEREGRINE FALCON. HERON. COOT.] Another extraordinary fact about the moulting of the drake is that, in moulting, he puts on the dress of the female. The moult is complete, but only after the whole of the small feathers have been changed are the wing- and tail-feathers shed, and as these are all shed at once, the bird is for some time incapable of flight. But while in this incapable condition he is no longer a drake in appearance--a bird of rich and conspicuous colouring--but has a dull mottled brown like the duck. This annual ‘eclipse,’ as Waterton called it, lasts for three or four months; and then there is a second, autumnal moult, of the body-feathers only, in which the rich colours of the male sex are recovered. The duck, in the meantime, moults only once in the year. A slight difference has been noted between the resident mallard that breeds in the British Islands and the mallard from the north that visits us in winter, the native bird being heavier. Gadwell. Chaulelasmus streperus. Beak lead-colour; head and upper neck light brown with darker mottlings; back marked with crescents of light grey on a dark ground; median wing-coverts chestnut; greater coverts blackish; primaries brown; secondaries brown and black, the outer webs forming a white speculum; rump and upper tail-coverts bluish black; tail-feathers dark brown with pale edges; lower neck dark grey, each feather with a pale grey margin; breast and belly white; flanks and vent grey; under tail-coverts bluish black; legs and feet orange. Length, twenty-one inches. _Female_: head and upper neck light brown mottled with dark; lower hind neck and upper parts brown; speculum and under parts white. * * * * * [Illustration: FIG. 81.--GADWELL. ¹⁄₁₀ Natural Size.]