594 



ANATOMY OF VERTEBRATES. 



465 



rinian cartilage;' both upper, b, and lower, c, vocal cords are 

 well defined, and directed obliquely downward to be inserted into 

 the thyroid about one-eighth of its length from the lower margin. 

 The ventricle, commencing by the chink, d, is continued upward 

 into an oblong flattened sacculus, a. The range of voice is con- 

 siderable, from the low grunt to the loud discordant squeal. 



In the Camel the wings of the thyroid meet at an almost right 

 angle, and unite along the mid part, leaving an upper and an 

 under notch. The upper cornu is represented by a slightly 

 prominent tubercle ; the lower cornu is more produced, over- 

 lapping obliquely the cricoid, and tied to a tubercle near its lower 

 border by short ligamentous fibres. The cricoid is a deep and 

 thick annular cartilage; the vertical extent anteriorly is about 

 half of that behind ; the upper border 

 has an oval facet on each side for the 

 arytenoids. The base of the arytenoid 

 developes an external, fig. 465, d, and an 

 internal process ; the body is lamelliform, 

 and expands above into a punctate softer 

 cartilage which curves outward. The 

 epiglottis, ib. a, has a median rising or 

 tubercle, h, on the hinder surface ; the 

 lower cords, c, c, from the base of the 

 arytenoids, are neatly defined, more linear 

 in the Llama than in the Camel; the 

 broad membranes, b. b, continued from 

 the anterior border of the arytenoids to 

 the base of the epiglottis, represent, by a 

 slight thickening of their lower border, 

 the upper cords ; a slit-like aperture be- 

 tween these and the lower cords leads to 

 moderately developed ventricles. The 

 thyroid cartilage is perforated by a laryngeal nerve and by a 

 vessel. 



In the Ox the thyroid alas are sub-equilateral, and united at ait 

 obtuse angle : the upper vocal cord is less marked than in the 

 Camel ; the lower one is rather longer, and vibrates so as to 

 produce the bellowing roar of the bull and the sonorous lowing 

 of the cow. 



In the Elk (Alces), the upper cornu of the thyroid, fig. 466, a, 

 is much produced ; the lower one is obsolete, and the roundel 

 angle there is connected by ligament with the cricoid tubercle. 

 The cricoid is short anteriorly, ib. b, and connected there by the 



Larynx exposed from behind, 

 Camel, cccxx. 



