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CHAPTER IV. 



Organs of Sound. — Ducks, Crane, Goat-Sucker, Bell- Bird, &c. — 

 Distance at which Sounds may be heard. — Plumage. — Structure 

 of Feathers. — Goose-Plucking. — Summer and Winter Plumage. 



From the organs of breathing we naturally proceed to those of 

 voice. The striking difference existing between those of birds 

 and other animals may, perhaps, be best explained by compar- 

 ing them with the organs of sound in the human species. We 

 utter sounds and speak through a certain tube, communicating 

 from the mouth to the lungs, called the trachea or windpipe, 

 which is furnished with very beautiful contrivances for the 

 purposes of sound. In like manner birds are provided with 

 windpipes ; but, unlike men and animals, they have a double 

 set of instruments, if they may be so called, one at the upper, 

 and the other at the lower end of the windpipe ; and as it is 



jffi^^^^ 



in the lower part of the windpipe chiefly that the peculiar 

 contrivance for uttering sounds is to be found, which may be 

 compared to a clarionet, or similar musical instrument, it so 



