Ornithology. 1 1 



Birds are two-footed animals, covered with feathers, and 

 furnished with wings. Like quadrupeds and the cetaceous 

 tribe, they have warm blood, a heart with two ventricles, and 

 two auricles, and lungs for the purpose of respiration ; but 

 they are distinguished from both by their feet, feathers, wings 

 and horny bill, as well as by the circumstances of their 

 females being oviparous. 



The elegant and beautiful coloring of many of the feathered 

 race, the graceful ease of their flight, their various music, 

 their tender solicitude for their offspring, their engaging 

 instincts, their susceptibility of domestication, and their sub- 

 servience to the sustenance of man, have, in all ages, contri- 

 buted to interest the latter in the study of their history. 



The structure of birds and their habits of life, are wonder- 

 fully adapted to the various functions which they are destined 

 to perform. The pointed beak, the long and pliant neck, 

 the gently swelling shoulder, the expansive wings, the taper- 

 ing tail, the light and bony feet, are all wisely calculated to 

 assist and accelerate their motion through the yielding air. 

 Every part of their frame is formed for lightness and buoyancy 

 their bodies are covered with a soft and delicate plumage, so 

 disposed as to protect them from the intense cold of the 

 atmosphere through which they pass ; tiieir wings are made 

 of the lightest materials, and yet the force with which they 

 strike the air is so great, as to impel their bodies forward with 

 astonishing rapidity, while the tail serves as a rudder to direct 

 them to the different objects of their pursuit. The internal 

 structure of birds is no less wisely adapted to the same purposes. 

 Their lungs have several openings, communicating with 

 corresponding air bags, or cells, which fill the whole cavity 

 of the body from the neck downwards, and into which the air 

 passes and re- p'dsses, in the process of breathing. 'J his is not 

 all; the very bones of birds are hollowed out with the 

 design of receiving air from the lungs, from which air pipes 

 are conveyed to the most solid parts of the f ody, and even 

 into the quills and plumelets of the feathers nhich are hollow 

 or spongy for its reception. As all these hol!ow parts, as v.ell 

 as the cells, are only open on the side communicating with 

 the lungs, the bird requires only to take in a full breath to 

 fill and distend its whole body with air, which, inconsequence 

 of the considerable heat of its body, is rendered much lighter 

 than the air of the atmosphere. By forcing this air out of 

 the body again, the weight becomes so much increased, that 

 birds of a large size can dart down from great heights in the 



