STERNUM OF THE ALBATROSS. 401 



rate height through the air, with light wing and with 

 great velocity ; again skimming close to the surface, 

 so that the points of their wings tip the water at every 

 stroke ; and yet again running along the water, with 

 expanded wings, which, though they seldom move, 

 float them so buoyantly, that they just touch the 

 water with the points of their webs, and thus paddle 

 swiftly along, collecting on the feathers of their 

 breasts that floating pellicle of oil which forms no 

 inconsiderable portion of their food, and which, when 

 they have wearied themselves in skimming, they lean 

 on the wave, and remove with the bill at their leisure. 



The albatross, which, though a very long-winged 

 bird, has a more heavy and gull-like flight than the 

 storm petrels, has, as already noticed, one notch in 

 each posterior angle of the sternum, by means of 

 which those parts of the bone are rendered feebler. 

 These birds are scavengers for larger matters rather 

 than skimmers of the oil of the sea, like the preceding 

 genus, but they are wide ranging scavengers, and, 

 when they are once on the wing, miles of ocean are 

 of little consequence to them in their range. 



The common petrels, and other birds which have 

 four notches in the posterior part of the sternum, are 

 inferior to the others both in the style and the rapidity 

 of their flight, and a connexion may be traced perhaps 

 as naturally from them through the puffins and auks to 

 the wingless birds, as that which is traceable from the 

 divers. The whole of this family may, however, be 

 considered as the most pelagic of all birds, because, 

 though there are others which are much more in the 

 water, or on its surface, there are none which have 

 equal power of wing, or are capable of extending 

 their excursions so far from the land. 



