LOCOMOTION. 213 



motions of animals, which may be primarily accounted 

 for by referring- to their exertions to procure sub- 

 sistence, and shelter, and the like, must always, in a 

 secondary point of view, give them beneficial exercise. 



WALKING OF BIRDS. 



"All living creatures,' 5 says Pliny, " have one 

 certaine manner of marching and going, according 

 to their several kinds, unto which they keep, and alter 

 not. Birds only vary their course, whether they go 

 upon the ground or flie in the aire. Some walke 

 their stations, as crowes and choughs ; others hop and 

 skip, as sparrows and ousels : some run, as par- 

 tridges, woodcocks, and snipes ; others again cast 

 out their feet before them, staulk and jet as they go, 

 as storks and cranes*." 



Aristotle has remarked that there is no animal 

 known to fly always as fish are known to swim, and 

 hence he shrewdly concludes that all birds can walk, 

 though such as have small feet are sometimes called 

 footless (Apoda)^ a conclusion which, considering 

 the former weight of Aristotle's authority, ought, we 

 think, to have prevented the older naturalists from 

 inventing so many fables respecting the bird of para- 

 dise ; fables which continue to be partly kept afloat 

 by the specific name (Apoda) still given to this bird 

 in systematic works, though the authors of these 

 works know well that, so far from the bird of paradise 

 being destitute of feet, it has actually very large 

 ones in proportion to its size ; so difficult it is to 

 eradicate any error once diffused through the medium 

 of books or of popular opinion. It may not be un- 

 instructive, however, to advert to some of the singu- 



* Holland's Plinie. x. 38. f Hist. Anim. i. 



