4:31 BIRDS. 



the skies like a thunderbolt, as it stoops upon its 

 quarry, and the Swallow, and the Albatross sweep 

 over geographical degrees in their long sustained 

 peregrinations. The perfection of their respiration 

 is perhaps only second to that of insects : the air 

 they breathe passes, not into theu' lungs only, but 

 penetrates to the remotest parts of their system, filling 

 theii' very bones with life, and endowing them with ac- 

 tivity and animation adapted to then- aerial existence. 

 No one can have examined the bony scaffolding 

 of the Pelican or the Albatross, without being struck 

 with the lightness of its proportions, when compared 

 with the dimensions of the full-plumed bird, of 

 which it once formed the support — a circumstance 

 that has not failed to arrest the attention even of 

 the muse of poetry : 



" Their slender skeletons, 

 So delicately framed and half transparent, 

 That I have marvelled how a bird so noble, 

 AVhen in his full magnificent attire, 

 With pinions wider than the king of Vultures, 

 And down elastic thicker than the Swan's, 

 Should leave so small a cage of ribs to mark 

 Where vigorous life had dwelt a hundred years." 



The accompanying engraving represents the skele- 

 ton of a Vulture, with the contour of the bird drawn 

 in outline, as it would appear if clothed with flesh 

 and feathers. The principal bones are numbered in 

 the figure, and we will refer to them seriatim, as it is 

 important to be acquainted with their appellations 

 and functions. 



The skeleton of a bird is composed of nearly the 

 same bones as that of a quadruped ; but their form 

 and disposition are different. The attachment of the 

 head to the spinal column consists but of a single 

 pivot, an arrangement that allows the bird to turn 

 its head so as to look directly backwards. The neck 

 is also very moveable ; and as these animals have to 

 collect their food with their beak, the length of their 

 neck is in proportion to the height of their legs, or, 

 in many water-birds, to the depth beneath the sur- 



