AMPHIBIOUS, _a._ That which can live in two elements. ANAS, _s._ The generic name of the duck tribe. The Duck, a genus thus characterised. Bill middle size, strong, straight, more or less depressed, covered with a thin skin, often more raised than broad at the base, which is either furnished with a fleshy substance or quite smooth, always depressed towards the point, which is rounded, blunt, and clawed, margins of the two mandibles toothed with plates, of either a flat or a conical form. Nostrils almost at the surface of the bill, at some distance from the base, somewhat oval, half closed by the flat membrane which lines the nostril. Legs short, feathered to the knees, drawn back towards the belly; three toes before, wholly webbed; hind toe free, articulated higher up on the flank, without a membrane, or having only the rudiments thereof. Wings of middle size; the first quill either as long as the second or rather shorter. Temminck divides the genus into four sections. 1. The Goose; 2. The Swan; 3. The Duck. A. Ducks having the hind claw naked. B. Ducks having the hind claw covered with a loose membrane. This genus, in which ornithologists have included all the Swans, Geese, and Ducks, amounts, according to the latest enumeration, to ninety-eight species, and about fourteen varieties; thirty-three of the former, and one of the latter, are accounted British birds. From the swan downward to the teal, they are all of a clean-plumaged, beautiful race of birds, and some of them exquisitely so. Those which have been reclaimed from a state of nature, and live dependent on man, are extremely useful to him; under his protection they breed in great abundance, and without requiring much of his time or care, lead their young to the pool almost as soon as they are hatched, where they instantly, with instinctive perception, begin to search for their food, which at first consists chiefly of weeds, worms, and insects; these they sift, as it were, from the mud, and for that purpose their bills are admirably adapted. When they are further advanced in life, they pick up the sodden scattered grain of the farm-yard; which, but for their assiduous searchings, would be lost. To them also are allotted large quantities of corn which are shaken by the winds from the over-ripened ears in the field. On this clean and simple food they soon become fat, and their flesh is accounted delicious and nourishing. In a wild state, birds of various kinds preserve their original plumage; but when tamed they soon begin to vary, and show the effects of domestication: this is the case with the tame goose and the duck, which differ as much from the wild of their respective kinds, as they do from each other.—_Bewick._ ANASARCA, _s._ A general dropsy, consisting of a watery fluid lodged beneath the skin.