88 Roaring in Horses. 



cords is designated the glottis vocalis, pars vocales, or inter- 

 ligamentous portion ; that between the arytenoid cartilages, 

 the glottis respiratoria, pars respiratoria, or inter-carti- 

 laginous portion. The entire space, in what is termed the 

 " cadaveric position " of cords and cartilages, is in shape 

 something like a lance-head. It varies considerably in 

 shape and dimensions during life, however, being that part of 

 the larynx in which movement chiefly takes place, especially in 

 respiration, the chink through which the air passes having 

 been appropriately termed "the portal of the breath of life." 

 It offers for consideration, on each side, the vocal cords, 

 vocal bands, and arytenoid cartilages, with the lateral 

 ventricles. Its narrowest part in front is limited by the 

 body of the thyroid cartilage and the origin of the vocal 

 cords therefrom, while its widest part behind is formed by 

 the cricoid cartilage. 



The " vocal cords," or inferior thyro-arytsenoid ligaments, 

 which extend nearly half the length of the glottis, are two 

 bands or ledges, paler in colour than the adjacent parts, 

 and composed of yellow elastic tissue, covered with thin 

 mucous membrane ; they are capable of considerable elonga- 

 tion and retraction, according to the movements of the 

 arytaenoid cartilages. Their surface is somewhat oblique, 

 the free border being slightly higher than the fixed one, 

 which is thicker ; this allows their thin free margins to meet 

 more easily and closely in neighing, coughing, and other 

 acts in which the glottis has to be closed. 



The "ventricular" or "vocal bands," situatedabove thevocal 

 cords, are longitudinal folds of mucous membrane enclosing 

 a small quantity of fibrous tissue, and containing numerous 

 glands, the secretion of which, mucus, serves to moisten the 

 vocal cords. They arise from the thyroid cartilage, and are 

 inserted into the anterior surface of the arytsenoid carti- 

 lages ; they can be closely approximated, so as to separate 

 the upper portion of the larynx from the two lower ones, 

 and thus form a narrow tube with a closed bottom. This 



