8 INTRODUCTION. 



respectively the three most perfect senses, which exercise a general 

 influence on the character. 



After sight, the most perfect of the senses in birds appears to be 

 hearing, which is even superior to that of the quadrupeds, and 

 scarcely exceeded in the human species. We perceive with what 

 facility they retain and repeat tones, successions of notes, and even 

 discourse ; we delight to listen to their unwearied songs, to the in- 

 cessant warbling of their tuneful affection. Their ear and throat 

 are more ductile and powerful than in other animals, and their voice 

 more capacious and generally agreeable. A Crow, which is scarcely 

 more than the thousandth part the size of an ox, may be heard as 

 far, or farther;' the Nightingale can fill a wider space with its music 

 tlian the human voice. This prodigious extent and power of sound 

 depend entirely on the structure of their organs ; but the support 

 and continuance of their song result solely from their internal 

 emotions. 



The windpipe is wider and stronger in birds than in any other 

 class of animals, and usually terminates below in a large cavity that 

 augments the sound. The lungs too have greater extent, and com- 

 municate with internal cavities, which are capable of being expanded 

 with air, and, besides lightening the body, give additional force to the 

 voice. Indeed the formation of the thorax, the lungs, and all the 

 organs connected with these, seem expressly calculated to give force 

 and duration to their utterance. 



Another circumstance, showing the great power of voice in birds, 

 is the distance at which they are audible in the higher regions of the 

 atmosphere. An Eagle may rise at least to the height of 17,000 

 feet, for it is there just visible. Flocks of Storks and Geese may 

 mount still higher, since, notwithstanding the space they occupy, 

 they soar almost out of sight ; their cry will therefore be heard from 

 an altitude of more than three miles, and is at least four times as 

 powerful as the voice of men and quadrupeds. 



Sweetness of voice and melody of song are qualities, which in 

 birds are partly natural and partly acquired. The facility with 

 which they catch and repeat sounds, enables them not only to bor- 

 row from each other, but often even to copy the more difficult 

 inflections and tones of the human voice, as well as of musical 

 instruments. It is remarkable, that, in the tropical regions, while the 

 birds are arrayed in the most glowing colors, their voices are hoarse, 

 grating, singular, or terrific. Our sylvan Orpheus, the Mocking-bird, 

 the Brown Thrush, the Warbling Flycatcher ; as well as the Linnet, 



