THE PENGUINS 283 



penguins are four species of Palaeospheniscus, and of Farapten- 

 odjjtes, from the Miocene rocks of Patagonia. It is also worthy 

 of note that remains of Palaeeudyptes are found in the Oamaru 

 freestone, which represents an old coral reef. In these circum- 

 stances, it is fitting that the penguins should be given some 

 latitude in regard to space in this New Zealand work. 



Evidently, they are specially adapted for an aquatic life. On 

 account of this adaptation, and not by degeneration, they have lost 

 the power of flight. The feathei-s on the wings and on the body 

 have been reduced until they are almost like scales, which form 

 a continuous covering over the body. The only fairly long 

 feathers with quills are in the tail, or form plumes on the head; 

 in the wings there are no quill feathers. 



They can dive better than any other birds. Under water, their 

 wings are used as a means of locomotion, their feet being 

 stretched straight out behind. They fly through the water as 

 other birds fly through the air. As, however, the bird is lighter 

 than the water, the principal stroke of the wing must be directed 

 upwards, so as to keep the body under the surface. For this 

 purpose, the muscles that give the up-stroke to the wing are 

 developed to a greater extent than in other birds, and there is 

 a consequent expansion of the scapular, a bone that springs from 

 the shoulder of the wing, and lies along the side of the back. 

 As the wing is reduced to a flipper, the bones have all become 

 modified, and are broader and flatter than in other birds, and 

 the first digit has become fused with the second. 



These modifications have turned the wings into strong swim- 

 ming paddles. So rapid is the flight of these birds under water 

 that the crested penguins and the rock hoppers spring out of the 

 water, with their wings close to their sides, and take long leaps 

 through the air like porpoises. 



Penguins are the only birds that can swallow their food under 

 water. To do this, however, they have not developed any 

 structural modiflcation. It is constant practice, not special 

 adaptation, that enal)les them to remain under water longer than 

 other birds can. The limit of their power to remain under, 

 without coming up to breathe, is not known. Sir John Murray, 



