226 HABITS OF BIRDS. 



like a bow*. In man, when this orifice is brought 

 into its narrowest compass, the opening- is dimi- 

 nished about one-third of its length, and is then 

 not more than from one-twenty-fourth to one-twelfth 

 of an inch in width, and about half an inch in length, 

 the sides or lips presenting a sharp edge, directed 

 upwards and inwards, which has with considerable 

 propriety been termed the vocal chords. 



Other physiologists take different views from 

 both Dodartf and Ferrein, and amongst those 

 M. Kratzenstein imagined the opening of the wind- 

 pipe to resemble a drum, with the head divided J; 

 and Blumenbach and Summering think it is more 

 analogous to a flute, a pipe, or an Eolian harp - 

 a stringed instrument played upon by the wind. 

 M. Majendie, again, who has given a very elaborate 

 description of the organs of the voice, refers us to those 

 instruments whose sound is produced by a reed, such 

 as the hautboy and the clarionet ||. We may remark, 

 however, respecting this hypothesis, ingenious as it 

 is, that the various tones of the voice are produced, 

 not by stopping the holes at different distances, as in 

 those reed instruments, but by varying the width of 

 the windpipe at its orifice or out-going, where the 

 principal organs are situated, and also by varying 

 the length of the tube of the windpipe. 



Another well-known physiologist M. Richerand^f, 

 questions the fact of thB voice being similar to a 

 reed instrument, and goes into a learned argument 



* Mem. Acad. pour 1741, pp. 40922 ; and Haller, Element. 

 Physiologiae, ix. 31, 17; and Young, $ect. i. 400 j and Phil. 

 Trans, for 1800, 1412. 



t Mem. de 1'Acad. pour 1700. 



J Tentamen Sonorum Vocalium, 4to. 1781. 



Blumenbach, Instit. Physiol. by Dr. EHiotson, ix. 87, and 

 Sbmmering, Comp. Human. Fabric, vi. 93. 



|| Pnysiologie, i. 2078. ^f Physiology, by de Lys. 



