VOCAL ORGANS. 231 



it may be observed, that the sound produced by 

 some of the larger birds is exactly similar to the 

 notes that proceed from a clarionet or hautboy in 

 the hands of an untutored musician. The inferior 

 glottis exactly corresponds to the reed, and produces 

 the tone or simple sound. The superior larynx 

 gives it utterance, as the holes of the instrument; 

 but the strength and body of the note depend upon 

 the extent and capacity of the trachea, and the hard- 

 ness and elasticity of its parts. The convolution arid 

 bony cells of the windpipe, therefore, may be com- 

 pared with the turns of a French horn, and the 

 divisions of a bassoon; and they produce the proper 

 effects of these parts in the voices of those birds in 

 which they are found*." The Abbe Arnaud com- 

 pares the voice of the hooping swan (Cygnus ferns, 

 RAY) to the sound of a clarionet, winded by a person 

 unacquainted with the instrument f. 



In birds, however, we meet with a very consider- 

 able diversity in the structure of the vocal organs, 

 particularly in the length and thickness of the tube 

 of the windpipe ; and that not only in different 

 species, but often in different sexes of the same 

 species, and especially among water-fowl. This was 

 observed even by the earlier naturalists. Aldro- 

 vand, for example, whom it has been the fashion 

 to consider as a mere fabulist, has given a very ex- 

 cellent account of the windpipe of the wild swan 

 ^Cygnus ferus, RAY) from his own observation, which 

 we shall here translate. 



*' The structure of this windpipe," he says, " is 

 worthy of high admiration; for in descending along 

 with the gullet, when it arrives at the throat, it does 

 not, as in other animals, enter the lungs in a straight 

 line, but rising over the shoulder-blade (claviculus), 



* Rees' Cyclopaedia, Art. Birds* 

 f Buffon, Oiseaux. Art. Cygne. 



