225 



CHAPTER XIII. 



VOCAL ORGANS OF BIRDS. 



As the peculiar calls of birds expressive of fear, 

 alarm, invitation, and the like, as well as the songs 

 of many of the smaller species, are amongst the 

 most obvious of their habits, even to those who 

 otherwise pay little attention to their economy, it 

 will be requisite, before we consider such call-notes, 

 to give some account of their vocal organs, as they 

 have been described by comparative anatomists, of 

 whom Fabricius and Kircher are amongst the ear- 

 liest, and Colonel Montagu and Mr. Yarrell the most 

 recent. 



The views which have been taken by physiologists 

 of the mechanism of the voice in man as well in 

 birds are so different, that it is by no means easy to 

 reconcile them. Galen, the celebrated Greek physi- 

 cian, compared this mechanism to a flute, very natu- 

 rally supposing it to be altogether of the nature of a 

 wind instrument*; and in modern times M. Dodartf 

 has advocated the same opinion, maintaining that 

 the tones vary according tolhe expansion or contrac- 

 tion of the orifice of the windpipe (Glottis). M. 

 Ferrein and Dr. Young, on the contrary, have 

 compared it to a violin or a harpsichord, the vocal 

 cords formed by the sinews or ligaments constituting 

 the orifice of the windpipe, being supposed to per- 

 form the office of strings, upon which the air acts 



* DeUsu Partium. 

 t Mem. Academic, for 1700, p. 244, and 1707, p. 66. 



