FEET OF BIRDS. 407 



Some of the more remarka!)lc deviations from what may be 

 considered as the standard conformation, may, however, for 

 a moment arrest our attention. 



The Ostrich is of all birds the one that presents the 

 greatest number of exceptions to the general rules which 

 appear to regulate the conformation of birds, and in many 

 of its peculiarities of structure it makes some approach to 

 that which characterizes the quadruped. Though this bird 

 is provided with wnngs,. it was evidently never intended 

 that they should be used for the purposes of flight. Hence 

 the chief muscular power has been bestowed on the legs, 

 which are remarkably thick and strong, and well fitted for 

 rapid progression. The sternum is flat, and does not present 

 the keel-like projection which is so remarkable in that of all 

 other birds. The clavicles do not reach the sternum, nor 

 even meet at the anterior part of the chest to form the fur- 

 cular bone: for as the wings are not employed in flying, the 

 usual office of that bone is not wanted. The form of the 

 pelvis is diflerent from the ordinary structure; for the pubic 

 bones, which in all other birds are separated by an interval, 

 here unite as they do in quadrupeds. 



The feathers are unprovided with that elaborate apparatus 

 of crotchets and fibres, which are universally met with in 

 birds that fly. The filaments of the ostrich's feathers, in 

 consequence of having none of these fibrils, hang loose and 

 detached from one another, forming the fine hair or down^ 

 which, however ornamental as an article of dress, must be 

 viewed, when considered physiologically, as a species of de- 

 generacy in the structure of feathers. 



The Penguin, in like manner, has a wing, which is, by its 

 shortness, totally unfitted for raising the body in the air: it 

 has, indeed, received a very diflferent destination, being 

 formed for swimming. In external form, it resembles the 

 anterior extremity of the turtle; but, still, we find it con- 

 structed on the model of the wings of birds; as if nature had 

 bound herself, by a law, not to depart from the standard of 

 organization, although the purpose of the structure is alto- 

 gether changed. As penguins are intended for a maritime 



