ACTIONS OF THE LARYNGEAL MUSCLES. 6ll 



plainly visible with the help of the laryngoscope. In the 

 utterance of grave tones, on the other hand, the epiglottis 

 is depressed and brought over them, and the arytenoid 



Fig. 172.* 



* Fig. 172. Three laryngoscopic views of the superior aperture of the 

 larynx and surrounding parts and different states of the glottis during 

 life (from Czermak). 



A, the glottis during the emission of a high note in singing ; B, in 

 easy and quiet inhalation of air ; C, in the state of widest possible dila- 

 tation, as in inhaling a very deep breath. The diagrams A', B', and C', 

 have been added to Czennak's figures', to show in horizontal sections of 

 the glottis the position of the vocal ligaments and arytenoid cartilages 

 in the three several states represented in the other figures. In all the 

 figures, so far as marked, the letters indicate the parts as follo\vs, viz. : 

 I, the base of the tongue ; c, the upper free part of the epiglottis ; e, the 

 tubercle or cushion of the epiglottis ; ph, part of the anterior wall of 

 the pharynx behind the larynx ; in the margin of the aryteno-epiglot- 

 tidean fold w, the swelling of the membrane caused by the cartilages of 



E E 2 



