23 1 6 TUBE-NOSED BIRDS, DIVING BIRDS, PENGUINS 



THE PENGUINS 

 Order IMPENNES 



Approximating to the diving birds (to which they also present certain re- 

 semblances in the structure of their soft internal parts) in the backward position 

 of their short legs and their upright posture when on land, the penguins of the 

 Southern Hemisphere differ from all other members of the class in two important 

 structural features. In the first place, the wings, in which 

 the quills are rudimentary, are transformed into paddles; and, 

 in the second, the short metatarsus is of great width, with 

 its three longitudinal elements incompletely fused together, 

 and separated from one another by small foramina. Conse- 

 quently, these birds can scarcely be said to have a true canon 

 bone. As regards their skulls, the penguins agree with the 

 other birds treated in this chapter in having the palate of the 

 cleft (schizognathous) type; and there are also hollows on the 

 RIGHT METATARSAI, forehea(i for the reception of glands. The feathers are pro- 

 BONE OF THE YEI^OW- vided with aftershafts, and the spinal feather tract is not 

 CROWNED PENGUIN, defined on the neck, while the oil gland is tufted. The young 

 although born covered with down, are at first helpless, and 



require to be tended for a long period in the nest. In addition to the rudimentary 

 condition of the wing quills, there are also no functional tail feathers; and it is 

 very noteworthy that the rudimental scale-like feathers with which the wings 

 are covered are more numerous than the quills and wing coverts of any other 

 birds. As additional characteristics of the skeleton, it may be mentioned that the 

 blade bone or scapula is remarkable for its great breadth, while the bones of the 

 wings are flattened; the humerus, which has no process on the outer side of its 

 lower extremity, being very short. In habits the penguins are marine and 

 carnivorous. 



The general appearance of these birds is so well known that it will be un- 

 necessary to say much on this point. We may mention, however, that the beak is 

 more or less elongated and straight, with its sides compressed and grooved, and its 

 tip sharply pointed; the slit-like nostrils being situated within the lateral grooves. 

 The three front toes are of moderate length and completely webbed; while the first 

 toe is very small, and united to the sides of the metatarsus. Although it is possi- 

 ble that the penguins may have some affinity to the diving birds, the structure of 

 the metatarsus seems undoubtedly to point to their being an extremely primitive 

 type, since it is difficult to believe that a metatarsus of this kind could have been 

 evolved from the canon bone of an ordinary bird by a kind of retrograde evolution. 

 This view is supported by the large number of the rudimental wing feathers, to 

 which allusion has been already made; and likewise by the circumstance that re- 

 mains of a very large penguin having been obtained in New Zealand from strata of 

 Eocene age, thus showing the extreme antiquity of the group. It may be added 

 that some writers regard the penguins as constituting a group entirely apart from 



