THP] PENGUINS. 



The Penguins constitute a group of oceanic birds peculiar to the Soutliern Ocean. 

 They are not intertropical, but range from the frigid to the temperate latitudes south of 

 the tropic of Capricorn, and in these seas take place of the Auks, and especially of the 

 Great Auk of the Northern Ocean. 



Adapted in their structure not for the land, on wliich" they arc constrained and 

 awkward, nor for the air, into whose regions Nature has forbidden them to arise, but for 

 the watery element, in which, like the seal, they are completely at home, they present in 

 the peculiarities of their organisation a subject of the highest interest. 



As the limbs of the seal are converted into paddles, in order to fit it for its destined 

 mode of life and the successful chase of its finny pre}', so the limbs of the penguins are 

 converted into aquatic organs, in order that they may propel these tenants of the deep 

 through the yielding water. And as the modified structure of one organ requires a 

 corresponding modification of another, so the conversion of the wings into aquatic paddles 

 in the case of the penguins, which can manifestly only be used with efiect as the body 

 is submerged to a certain depth, so do they exhibit a correspondence in the weight, the 

 figure, and the clothing of the body, in the structure of the skeleton, and in the very 

 texture of the bones. 



The weight of the body itself is specifically greater than in other birds. Were the 

 penguin, with its shape unaltered, S2)ecificall}' as light as the swallow or the tern, it 

 would float like a cork ; diving would be a laborious task, and its paddle-like wings — 

 incapable of being used except while the body is submerged — comparatively useless. 

 Hence we find it, in aU respects, adapted to its circumstances. 



Its weight is such as to sink the bird almost to the head in the water, and consequently 

 such as incapacitates it for flight, even were its wings formed as in aerial birds. Instead, 

 therefore, of having a light skeleton, consisting of hollow air-fiUed bones, with their 

 walls, the penguin has a dense, heavy, firmly-knit, osseous fabric. All the bones are 

 compact and dense ; they have no aperture for the admission of air ; and the slight 

 degree of hoUowness of those of the limbs is filled with thick oily marrow. The skin is 

 thick and oily ; the muscles are darker-coloured and heavy. Still further ; the large air- 

 cells, so conspicuous in the ca\'ities of the chest and abdomen of aerial birds, and which 

 are connected with the lungs, are here not only few in number, but of small extent. 

 In many birds these air-cells are carried out even between the skin and the muscles, 

 not only on the body, but even along the limbs, so that the whole system is, as it 

 were, inflated; but in the penguin this admirable structure, not being needed, is 

 wanting. 



Nor is it only in the weight of its frame that the penguin shows its adaptation to the 

 watery, and not to the aerial element ; for its figure, its clothing, and the organisation 

 and place of its limbs, indicate its destiny with equal clearness. Thus the body is 

 compressed and boat-shaped, of an elongated form, covered with a dense, waterproof 

 covering of sUk}' feathers, closely compacted together, so that the whole presents a 

 smooth and glossy surface. The vest of feathers, thus modified, is closely pressed to 

 the skin. 



In some of the water-birds the limbs seem, like the hinder flappers of the seal, to 

 terminate the body, and are, moreover, modified with efficient paddles. But in the 

 penguin the situation of the legs is so posterior, that, in order to maintain its balance 



