THE VOICE 227 



during expiration, but sounds may also be 

 produced by inspiratory efforts. The larynx 

 is formed of cartilages connected by ligaments 

 and more or less capable of being moved on 

 each other by muscles, the muscles of the 

 larynx. The chief cartilages are the thyroid 

 or shield forming the prominence known as 

 Adam's apple. Immediately below it is the 

 cricoid or ring cartilage, shaped somewhat 

 like a signet ring, with the signet directed to 

 the back. On the signet there rest two small 

 cartilages, the arytenoids. These are pyra- 

 midal in shape, the bases of the two pyramids 

 resting on the signet of the cricoid while the 

 apices are directed upwards. The true vocal 

 cords are two membranes or ligaments stretched 

 from the base of each arytenoid forwards to 

 the thyroid. They are formed of connective 

 tissue fibres, with which are intermingled 

 many fibres of elastic tissue. Running in 

 the larynx from before backwards they leave 

 a narrow chink between their free edges 

 called the glottis. During calm inspiration 

 the glottis is widely opened, but on the 

 approach of an expiration the free margins 



