the Physiology of the Htimaii Voice. 347 



c c. The thyro-arytenoid muscles. 



d d. The lateral crico-arytenoideal muscles. 



c. The edge of the thyroid cartilage. 

 ff. The arytenoid cartilages, with their perpendicular 

 pi'ojections cut through at f. 

 g. A portion of the transverse arytenoid muscle. 

 hh. The posterior crico-arytenoid muscles. 

 Fig. 4. An internal anterior view of the larynx, produced 

 by a section transverse to its aniero-posterior diameter. 

 a. The epiglottis. 

 b b. The os hyoides. 

 c c. The segments of the internal surface of the thyroid 



cartilage. 

 d d. The thyro-arytenoid muscles. 

 e e. A portion of the thyro-epiglottideal muscles. 

 ff. The pseudo-glottis. 

 g g. The sacculus laryngis. 

 h Ji. The cricoid cartilage. 

 i i. The chords vocales, lying nearly parallel to the 



axis of the vocal tube. 

 Jc. The internal aspect of the trachea. 

 Fig. 5. The posterior segment corresponding to fig. 4. 

 a. The pharynx. 

 bb. The arytenoid cartilage invested by its mucous 



membrane. 

 CO. The chordae vocales. 

 dd. The thyro-arytenoid muscles. 

 e e. The wings of the thyroid cartilage. 

 ff The cricoid cartilage. 

 g. The trachea. 

 Fig. 6. This figure represents a transverse section of the 

 larynx : the thyro-arytenoid ligaments are turned perpendi- 

 cular to the axis of the vocal tube ; the glottis is seen in the 

 true vibrating position. 



aa. K section of the thyro-arytenoid ligaments. 

 b b. The pseudo-glottis, 

 c c. A section of the thyro-arytenoid muscle. 

 Fig. 7, Is an external side view of the larynx, showing the 

 action of the crico-thyroid muscles, by which the cricoid is 

 rotated with the thyroid cartilage, and the tension of the local 

 ligaments affected. 



a. The situation of the insertion of the vocal ligaments. 



b. The upper posterior edge of the cricoid cartilage, to 



which the arytenoids are articulated. 



c. The left crico-thyroid muscle. 



d. The articulation of the thyroid to the crico-cartilage. 



e. The dotted line, showing the position of the cricoid 



2 S2 



