CHAPTER XX 



THE TUBE-NOSED BIRDS, DIVING BIRDS, AND PENGUINS 

 ORDERS TUBINARES, PYGOPODES, AND IMPENNES 



WITH the exception that they are all thoroughly aquatic in their habits, the 

 tube-nosed birds, as represented by the albatrosses, petrels, and shearwaters, have 

 little or nothing in common with the diving birds, as exemplified by the auks, 

 divers, and grebes, or with the penguins; and it is merely as a matter of convenience 

 that the three groups are treated in the same chapter. They accordingly need no 

 collective notice, so that we at once proceed to the consideration of the leading fea- 

 tures of the first of the three groups. 



The members of this order take their name from the circumstance 

 that the external nostrils are produced into tubes lying upon the sur- 

 face of the beak and directed forward; this feature being absolutely 

 peculiar, and serving at once to distinguish them from all other birds. The horny 

 sheathing of their beak is composed of several distinct species, separated from one 

 another by more or less marked grooves, and the tip of the beak is sharply hooked. 

 In the skull the palate is of the slit (schizognathous) type; while its nasal apertures 

 are oval, or holorhinal, and the angle of the lower jaw is abruptly truncated be- 

 hind. As in so many sea birds, the upper aspect of the skull has very deep grooves, 

 which, however, are always separated from one another on the forehead by a wide 

 bar. The vertebrae of the back are articulated with one another by the usual saddle- 

 shaped surfaces. In the wings, which are generally of great length, the humerus 

 resembles the corresponding bone of the gulls in having a well-marked process on 

 the outer side of its lower extremity, although the perforations in the basal bone of 

 the second digit of the wing characterizing that order are wanting. The tibia, or 

 leg bone, differs from that of all the birds hitherto considered in having a flattened 

 plate-like crest projecting upward on its front aspect some distance above the level 

 of the head of the bone. The feet are characterized by the small size or even occa- 

 sional absence of the first toe, while the three front toes are completely webbed. In 

 the plumage there is a well-defined bare tract on each side of the neck, and the oil 

 gland is furnished with a tuft of feathers. The young, which are born in a help- 

 less condition, and are fed for a considerable period in the nest by the parents, are 

 clothed with down, arranged in a somewhat complex manner. 



In habits, all the tube-nosed birds are marine and carnivorous, subsisting en- 

 tirely on either carrion, cuttlefish, or crustaceans, together with such refuse as they 

 can pick up. They are all birds of sustained and powerful flight; and, with the ex- 

 ception of the members of one aberrant genus, are swimmers rather than divers. 

 In appearance several of them, more especially the fulmars, present a marked simi- 

 larity to the gulls; the plumage in this instance being of the gray and white hue 

 144 (2289) 



