OF THE VOICE. 



65 



mistake for it the buzzing of the bee, which is merely a 

 noise create i by the vibration of the wings ; nor the grating 

 shriek of the Locust, (grasshopper,) caused by the friction of 

 his legs against his wings ; nor the shrill noises of the cricket, 

 or the tell-tale call of the katydid, produced by the friction 

 of the wing covers upon each other, and in numerous similar 

 cases which might be cited. 



122. Consequently, were the mammals, the birds, and the 

 frogs to be struck out of existence, the whole Animal King- 

 dom would be dumb. It is difficult for us, living in the midst 

 of the thousand various sounds which strike our ear from all 

 sides, to conceive of such a state. Yet such a state did 

 doubtless prevail for thousands of ages, on the surface of our 

 globe, when the watery world alone was inhabited, and be- 

 fore man, the birds, and the mammals were called into being. 



123. In man and the mammals, the voice is formed in an 

 organ called the larynx^ situated at the upper part of the 

 windpipe, below the bone of the tongue, (a.) 

 The human larynx, the part called Adam's 

 apple, is composed of several cartilaginous 

 jjieces, called the thyroid cartilage, (Z>,) the 

 cricoid cartilage, (c,) and the small arytenoid 

 cartilages. Within these are found two large 

 folds of elastic substance, known by the name Fig- 22. 



of the vocal cords^ (m.) Two other analogous folds, the 

 superior ligaments of the glottis, (n,) are' situated a little 

 above the preceding. The glottis (o) is the space between 

 these four folds. The arrangement of the vocal cords, and 

 of the interior of the glottis in man, is indicated by dotted 

 lines, in Fig. 22. 



124. The mechanism of the voice is as follows : the air, 

 c its way to the lungs, passes the vocal cords. So long as 

 tliese are in repose, no sound is produced ; but the mome ii 

 they ar< made tense they narrow the aperture, and oppose 



