3*26 
CHAPTER X. 
Plate XXL — the larynx. 
Fig. 1. The larynx, pharynx, &c. a, the os hyoides, h, the epiglottis 
pressed down, thus covering the glottis, or opening of the larynx; 
as it does in the act of deglutition. 
Fig. 2. Exhibits the larynx, and trachea; which is a continua¬ 
tion of the former; b, the epiglottis ; g, the arytenoid cartilages; e, 
the thyroid cartilage, exceedingly strong, for the protection of the 
upper part of the air tube; d, the cartilaginous ringlets of the trachea 
or wind-pipe, each forming nearly two-thirds of a circle, and com¬ 
pleted by f a soft membrane, which, from its apposition to, e, Fig. 
1, the oesophagus, accommodates itself to tne substances passing 
into the stomach. 
Fig. 3. The larijnx or upper part of the wind-pipe of a bird. 
This is called the inferior larynx, where the vocal organ is formed 
by a compression of the trachea, for it is here contracted into a 
narrow chink, and divided into two openings by a slender bone, 
or tense membrane, which, in producing sounds, resembles the 
mechanism of a musical instrument. In the plate this part of the 
larynx is a little turned up to show the tendinous band at this ex¬ 
tremity stretched across it, which is furnished from the surrounding 
parts with muscles to modulate the tone. 
