of the United States. 
381 
equal to the middle toe, not extremely compressed ; tibia 
smooth ; toes moderate, middle longest, inner shortest ; webs 
full, entire, blit not very large ; hind toe equal to a phalanx 
of the middle, simple, touching the ground at tip. Wings 
moderate, acute; primaries elongated, first and second, or 
second only, longest. Tail of from fourteen to twenty 
feathers. 
Female very different from the male in full plumage. 
Young generally more or less resembling the female. Moult 
twice in the year, the female partially, the male completely, 
assuming in summer the humble dress of the female. Plu- 
mage thicker than in the Geese, but not so thick as in the 
Swans and Fuligulfe. A mirror or speculum on the wing in 
most species. Colors of the female dull, grayish. Trachea 
swelling at the bifurcation into cartilaginous capsules. 
Migrate in large flocks : in autumn and winter keep in fresh 
water and rivers, affecting green shores and sedgy places, es- 
pecially shallow water, where they can reach the bottom with 
their bill, without diving. Somewhat nocturnal : feed and 
travel by night. Food chiefly vegetable, plants and seeds, 
but also aquatic animals. Disposed to polygamy : build in 
the grass, more or less near water, some in hollow trees : 
nest lined with down : eggs numerous. Female alone incu- 
bates, without any assistance from the male, and covers the 
eggs with the lining of the nest and other materials when 
obliged to leave them. The male does not trouble himself 
about the young. Walk comparatively well, but not so well 
as the Geese, with the body poised, and the feet close 
together. While swimming raise the tail and stretch their 
body. Avoid deep water : dive only when compelled by 
necessity, or in the breeding season. Flight comparatively 
light, often high, whistling. 
Spread all over the globe : species numerous, more so in 
temperate regions. We divide them into four subgenera, two 
only of which are found in the United States, 
Ygl. If. 48 
