538 



RESPIRATORY SYSTEM OF THE OX 



peculiar form. The lamina is oblong, and curves ventro-laterally from the anterior 

 extremity of the dorsal parietal cartilage, with which it is connected. The cornu 

 springs from the lateral part of the lamina and curves dorso-laterally into the outer 

 wing of the nostril; it carries on its extremity a small transverse bar, thus having 

 some resemblance to the fluke of an anchor. 



The nasal cavity is short, wide anteriorly, narrow behind. It is not com- 

 pletely divided by the septum, which in its posterior third is separated from the 

 floor of the cavity by an interval that increases from before backward (Figs. 140, 

 141) . The middle meatus is very narrow, and divides posteriorly into two branches ; 

 the upper division leads to the ethmoidal meatuses, and communicates with the 

 frontal sinus and the cavity of the dorsal turbinate. Anterior to the division are 

 communications with the upper cavity of the ventral turbinate and the maxillary 

 sinus. The main facts in regard to the sinuses were stated in the Osteology. 



THE LARYNX 



The larynx is more compact than in the horse, and presents numerous differ- 

 ential features. The cricoid cartilage is compressed laterally. The lamina is not 

 distinctly marked off from the arch; it slopes downward and backward and has a 



Arytenoid Processus Lamum of Lateral lobe 

 cartilage muscularis cricoid cartilage , ., • , 



Epiglottis 



Arch of cricoid Isthmus of 

 cartilage thyroid 



Thyroid Laryngeal 

 cartilage 'promirience 



Fig. 477. — Cartilages of Larynx and Part of Trachea of Ox; Left View. 



Outline of thyroid gland indicated by dotted line. 



1, Anterior cornu of thyroid cartilage; 2, thyroid foramen; 3, ligament converting notch into foramen; 4, posterior 



cornu of thyroid cartilage; 5, capsule of thyro-arytenoid joint. 



large median ridge. The thyroid cartilage is complete ventrally, i. e., the laminae 

 are united to form a long plate which is notched in front and behind; the laryngeal 

 prominence is small and is situated posteriorly. The height and thickness of the 

 cartilage increase from before backward. The posterior cornua are curved and are 

 about an inch long; they form syndesmoses with the cricoid cartilage. The short 

 anterior cornua unite similarly with the hyoid bone; near them there is a foramen 

 or a notch on each side for the passage of the anterior laryngeal nerve. The epi- 

 glottis is short, oval in outline, and its apex is rounded; its base rests on the "thyro- 

 hyoid membrane, to which it is rather loosely attached. The cuneiform cartilages 

 are absent. The arytenoid cartilages present only slight differences. The muscular 



