228 



THE CAT. 



[CHAP. vm. 



and more developed behind than elsewhere. Its lower border is 

 slightly undulating, and is connected by membrane with the upper- 

 most cartilage of the trachea. Its convex upper posterior border 

 has a scarcely perceptible median notch, and on each side of this is 

 an oval, convex, articular facet. Internally this cartilage is lined by 

 the mucous membrane of the larynx. 



The third median cartilage is the epiglottis, which is acutely 

 pointed above and very obtusely so below, where it is attached by 

 ligament to the inside of the thyroid. The posterior (dorsal) surface 

 of the epiglottis is concave from side to side. Vertically, its anterior 

 (ventral) aspect is concave above and convex below (Fig. 106). It 

 is invested with mucous membrane both in front and behind, except 



Fig. 107. THE LARYNX AND GLOTTIS OF THE CAT. 



Aper 



B. The same dilated. 



C. Opening into the larynx. 

 a. Arytenoid cartilages. 



ac. False vocal cords. 



c. Epiglottis. 



fv. Crico-epiglottic ligaments. 



v. True vocal cords. 



D. Vertical section through the trachea and 



oesophagus. 



a, ac, e, and/y, as in figure C. 

 Between ac and v is the ventricle of the 



larynx. 



cr. Cricoid cartilage cut through. 

 a. (Esophagus. 

 t. Trachea. 



the lower part of its front surface, where it is attached to the tongue 

 and hyoid by ligaments that which connects it with the hyoid being 

 elastic. It is connected on 'each side by a strong fold with (Fig. 

 107,/r) the side of the cricoid cartilage close to the base of the 

 arytenoid cartilages. 



The two arytenoid cartilages rest each on one of the two oval 

 articular surfaces before mentioned as situated one on each side of 

 the median posterior notch, in the upper border of the cricoid 

 cartilage. Each arytenoid cartilage is irregularly pyramidal in 

 shape, the base of each pyramid resting on the cricoid. The summits 

 of the arytenoid cartilages curve somewhat towards each other. 



A good many ligaments connect the different portions of the 

 larynx. Thus there is the thyro-epiglottic and hyo-epiylottic con- 

 necting the epiglottis with the thyroid and os hyoides respectively. 



