364 VERTEBRATA. AVES. 



toe. They inhabit precipitous rocks on the sea- 

 coasts, where they breed in vast congregations. We 

 have seen the air round some high barren rocks in 

 the Gulf of St. Lawrence, called the Bird Islands, 

 so filled with these birds, as to appear at a distance 

 as if enveloped in smoke. The Great Guillemot ( U. 

 Troile) breeds on the coasts of Scotland : the egg is 

 remarkable for its great size, conical shape, and the 

 irregularity of its markings, scarcely two being found 

 alike. The glaire hardens, by boiling, only so far as 

 to become a pellucid jelly. 



Aptenodytes,* the Penguin. 



Through the Puffins, whose small wings are just 

 able to sustain them an instant in the air, and the 

 Auks, in which these organs are totally deprived of 

 the power of flight, we come to the Penguins, the 

 lowest group of Birds, whose minute wings, covered 

 with vestiges of feathers that look like scales, 

 strongly resemble in appearance and use the flippers 

 of a Turtle, and whose feet are placed so far behind 

 that the bird, when standing, which it can do only in 

 a plantigrade fashion, is erect. The whole of the 

 foot is widened and flattened, like that of a Seal. 

 Utterly deprived of flight, the motion of walking is 

 almost denied to them, and one species can move on 

 land only by short, shuffling leaps, or by drawing 

 themselves awkwardly along on their bellies. Once 

 in the water, however, " they swim with the ease and 

 rapidity of a fish, springing several feet over any ob- 



* A, without, (TTE^ov, pteron, a wing, and & 



