250 



AVES. 



incapable of flight, and are almost entirely confined to the water. 

 Most of them also dive with great skill, either shooting down into 

 the water from the air or suddenly diving beneath the water while 

 swimming. The form of the beak varies as much as does the 

 structure of the wings. Sometimes the beak is much arched and 

 armed with cutting edges, and sometimes flat and broad; some- 

 times elongated and pointed. The form of the beak is correlated 

 with the mode of subsistence : in the first case we have to do with 



predatory birds, which especially prey 

 on fishes, in the last case with birds, 

 which live on worms and small aquatic 

 animals, but also on fishes. The swim- 

 ming Birds, with broad soft-skinned 

 beak, search in the mud and feed 

 not only on worms and small aquatic 

 animals, but also on seeds and vege- 

 table matters. The Natatores are 

 gregarious, and exist in great flocks 

 on the sea coasts or on inland waters, 

 but some of them are also found on 

 the high seas, far from land. Most 

 of them are migratory. They nest 

 near the water, often in common 

 breeding places, and lay a few eggs 

 either directly on the ground, or in 

 holes, or in simple, rudely-made nests. 

 Many of them are of great impor- 

 tance to man, partly on account of 

 their flesh and eggs, and partly of 

 their down and skins, and partly also 

 on account of their excrements, which are used as manure (guano). 



FIG. 660. Aptenodytes patagonica 

 (from Brelrm) . 



Fam. Impennes (Penguins). The wings are fin-like, without remiges, covered 

 with small scale-like feathers. The tail is short, with stiff feathers. The short 

 swimming-feet have a reduced forwardly-directed hind toe, and are placed so 

 far back that on land the body must be carried almost vertically. They are 

 excellent divers. In the breeding season they stand upright and arranged in 

 long rows the so-called schools. They lay only one egg in a depression in the 

 ground, and keep it in a vertically upright position during incubation : but they 

 can also carry it about buried in the down between the legs. Both sexes 

 participate in incubation. Aptenodytes patagonica, Forst., King- Penguin 

 (fig. 660) ; S/pneniscAiS demersus L., Black-footed Penguin, South Africa and 

 America ; Eudyptes elirysocoina L., South Sea, Patagonia. 



