230 HABITS OF BIRDS. 



a singular character in the throat or cheek, directly 

 communicating with the orifice of the windpipe, on 

 which the croaking principally depends*. 



Jn birds, again, the windpipe is very different in 

 structure from that of other animals, and in song- 

 birds is peculiarly and admirably adapted to that 

 sweet and varied music with which we are so often 

 delighted in the woodlands. The whole extent, in- 

 deed, of the windpipe in such birds, may be regarded 

 as one vocal apparatus ; the upper part (larynx) being 

 divided into two sections, or, as they may rather, per- 

 haps, be considered, into two distinct organs. That 

 which is more complicated, or in which the parts are 

 more numerous and elaborate, is placed at the lower 

 end of the windpipe, at the place where it divides, 

 in order to be distributed through the lungs : the 

 more simple, or that in which the parts are fewer, 

 occupies its usual situation at the upper end of the 

 windpipe, which, however, is destitute of the valve 

 or lid (epiglottis) which is found in man. From 

 this view of the vocal organs in birds, we may con- 

 sider their lungs and windpipe as forming a natural 

 bag-pipe, in which the lungs constitute the pouch 

 and supply the wind, the windpipe itself forming 

 the chanter or pipe ; the lower or more complicated 

 part (glottis inferior) being the reed or mouthpiece 

 which produces the simple sound ; and the upper 

 part (glottis superior) the finger-holes, which modify 

 the simple sound into an infinite variety of distinct 

 notes f- 



Dr. Macartney has justly remarked, that " a very 

 little comparison of the mechanism of wind musical 

 instruments with the organs of the voice in birds, will 

 show how nearly they are allied to each other; and 



* Good's Study of Medicine, i. 4'29 ; second edit, 

 t Idem, i.461. 



