DUSKY DUCK. 73 
duck, being the most common and most numerous of all those 
of its tribe that frequent the salt marshes. It is only partially 
general observations regarding their economy, with an enumeration of 
those species onitted by Wilson which have been since discovered, may 
not be deemed improper. 
The Anatide, or those birds generally known under the denomination 
of ducks, geese, and swans, taken as a family, will range with groups 
of great extent and varied form, as the falcons, the parrots, or pigeons, 
and will present similar modifications. The characters of the greater 
part of the groups which inhabit the northern and temperate regions of 
the world have been already drawn by Dr Leach and Dr Fleming, and 
one sub-family has been more lately analysed by Mr Swainson, as far 
as our knowledge of them extends, apparently with tolerable accuracy. 
They, however, want comparison with the tropical forms, which depart 
so much in their manners from those we are accustomed to see, and by 
which our opinions have hitherto been led, The wood ducks, constitu- 
ting Mr Swainson’s genus Dendronessa, the long-legged whistling ducks 
of India, those birds allied to the little Gambia goose, and those approach- 
ing in their form to the Grallatores, all want our close examination. 
In distribution, the Anatide extend over the world, from the warmest 
tropics to the extreme arctic cold, but exist in greatest abundance near 
the confines of temperate regions and in northern latitudes. Their 
habits may be called truly aquatic, as the presence of water is necessary, 
even in the most aberrant forms, for their healthy support. Some 
groups are exclusively aquatic, and never quit the sea or large 
inland lakes, except during the season when the duties of incubation 
for a while call them to the shore. These may be termed pelagic or sea- 
ducks, and feed on fish and molusce ; others delight in lakes and rivers 
as well as the sea, resort more frequently to the land, seek the same 
nourishment, and both are expert divers. Some hold a middle way, 
are as much on land as on water, and, in addition to the food of the 
truly sea species, live on the spawn of fresh-water fish, insects peculiar 
to muddy banks and slimy pools, with vegetables, such as the tender 
shoots of the grasses or newly-sown grains, or, while on the shores, upon 
the Zostera marina ; while one or two forms resemble the grallatorial 
birds, and are more independent of water and aquatic nourishment. 
In their breeding-places, they show a like variety, choosing the reedy 
banks of lakes and rivers, the treacherous morass, the cliffs and desert 
sands of the sea-shore, the burrows of various animals, the hollows of 
decaying trees in the stupendous forests of America, or in India the 
welcome shade of the sacred banyan. 
Their uses are various and extensive, either as food, or their skins, 
feathers, and down, for commerce and articles of wearing apparel, or 
