180 NATUEAL HISTOET. 



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 homy 

 laminsB 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 

 charaetei'istios 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 maybe divided into two classes, 

 those which frequent inland shallow waters, and those 



