FEEDERS. 73 



tially changed by long continuance on a different 

 kind of food ; and it is by no means improbable that, 

 in some of those species which live in great part upon 

 insects at one season of the year, and chiefly upon 

 vegetable substances at another, the stomach may 

 undergo seasonal changes. 



In proportion as any animal, whether bird or not, 

 13 more vegetable in its feeding, its abdomen, in a 

 natural and healthy state, is always the more bulky in 

 proportion to the whole body. This is very conspi- 

 cuous in the mammalia, (in which the size and distinc- 

 tions are more easily seen,) in which all the grazing 

 tribes are full, and all the carnivorous ones lank in the 

 belly ; but it holds also in birds, though in them it is 

 less conspicuous, as the whole body is covered with 

 feathers, and the several parts are not so easily dis- 

 tinguished from each other. If, however, we attend 

 carefully to the outline of their forms, we may, in most 

 cases, discover a greater uniformity of thickness 

 throughout in the vegetable feeders. Tliis appears 

 not only in the larger birds, in which the difference of 

 other habits maybe supposed to have some effect, but 

 even in the small birds. 



Generally speaking, too, vegetable feeding birds 

 are not so well winged as those which feed upon 

 animal matters. All the gallinaceous birds are heavy, 

 comparatively bad fliers, and take only very low and 

 short flights ; while the birds of prey are among the 

 most powerful fliers in the whole class ; though even 

 these are perhaps not so constantly on the wing, or 

 so very long flighted, as some of the tribes which feed 

 chiefly upon insects. In accordance with this forma- 

 tion, the vegetable feeders are not so regularly 

 migratory. Some of them, indeed, change their 

 abodes to considerable distances within the same 



