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DIVISION OF THE CLASS OF BIRDS INTO ORDERS. 



Of all classes of miimals, that of Birds is the most strongly characterized, 

 that in which the species have the greatest mutual resemblance, and 

 which is separated from all others by the greatest interval; circumstances 

 wliich, at the same time, render its subdivision the more difficult. 



Their distribution is founded, like that of the Mammalia, on the organs 

 of manducatiou or the bill, and on those of prehension, that is, still on 

 the bill, and more particularly on the feet. 



The first that arrest our attention are the palmated feet, or those in 

 which the toes are connected by membranes — such distinguish all Swim- 

 ming Birds. The position of these feet behind; the length of the ster- 

 num ; the neck, often longer than the legs, to enable it to reach below ; 

 the dense, polished plumage, impermeable to water, all concur with the 

 feet in making good navigators of the Palmipedes. 



In other birds, which most commonly are partially web-footed, at least 

 between the external toes, we observe elevated tarsi; legs divested of 

 feathers at their lower extremities ; a long, thin shape, and in fine, all the 

 requisites for wading along the shores of rivers to seek their food. Such, 

 in fact, is the regimen of the greater number ; and although some of them 

 inhabit dry grounds, they are called Shore-Birds, or Waders. 



Among the true land birds, the Gallinacece, like our domestic Cock, 

 have a heavy carriage, a limited power of flying, a moderate bill, the 

 upper mandible of which is arched; the nostrils partly covered by a soft 

 and inflated scale ; the toes almost always indented on the edges, and 

 short membranes between the bases of the anterior ones. They fly hea- 

 vily, and but a short distance at a time. Their chief food is grain. 



Birds of prey have a hooked bill, the point of which is sharp, and 

 curved downwards; the nostrils pierced in a membrane which invests the 

 whole base of that bill, and feet armed with vigorous talons. They live 

 on flesh, pursue other birds, and are consequently, for the most part, 

 vigorous in flight. The greater number have still a slight web between 

 the external toes. 



The Passerines comprise many more species than all the other families ; 

 but their organization presents so many analogies that they cannot be 

 separated, although varying greatly in size and strength. Their two ex- 

 ternal toes are united at the base, and sometimes for a part of their 

 length. 



Finally, the name of Scansorice, or Climbers, has been given to those 

 birds whose external toe, like the thumb, is directed backwards, because 



