180 NATURAL. HISTORY. 
the peculiar waddling gait which is so familiar to us in 
the Duck. Their plumage is dense, and it is oiled by a 
Fig. 147.—Foot of Gannet. 
secretion from glands, which keeps it from being pene 
trated by the water. Their necks are long, to enable 
them to reach their food. They are the only birds, Cu- 
vier remarks, in which the neck is longer than the legs. 
There are five families: Ducks, Divers, Auks, Gulls, and 
Pelicans. 
292. The Duck family have broad bills with horny 
lamin at the edges, which act as a filter, allowing the 
water to escape, but retaining substances which are in it. 
While this is going on, the tongue, which is soft and well 
endowed with nerves, is informing the animal what is 
and what is not worthy of being retained, or, in other 
words, selecting its food. There are nerves in the bill, 
also, which assist in this selection. The food is various, 
consisting of insects, worms, mollusks, grains, etc. These 
birds are distributed widely over the globe, and are usu- 
ally migratory. The flights of the Wild Geese in their 
military order are familiar to us. From the Wild Geese 
and Ducks come the domesticated ones, As the Goose 
lives more on land than the Duck, its legs are not set so 
far back, and it walks better. It seems to partake of the 
characteristics of both the Swimmers and the Waders. 
As it lives so much on land, its food is principally grains 
and grass. 
293. The true Ducks may be divided into two classes, 
those which frequent inland shallow waters, and those 
