1492 



VOICE. 



dom of motion to inferior ligaments. Voice bases fixed to the arytenoids. L. 2 in. Supe- 

 acute, rior vocal ligaments not prominent. Ventricles 



of Morgagni oval, deep, cc(fig. 906) Epiglottis 



Fig. 90 k 



Fig. 903. 



1. Larynx of the Rabbit laid open. 



2. Side view of the same, externally. 



a, epiglottis ; b, thyroid; d, cricoid ; c, crico -thy- 

 roid ligament ; e, trachea. 



Hi/strix cristata, Porcupine. Vocal liga- 

 ments absent. Ventricles of Morgagni none. 

 Voice mute. 



Castor Fiber. The Beaver. Larynx : II. 

 0'4*.5 in. Epiglottis triangular, having a vertical 

 rap he upon its posterior surface terminating 

 in a sac bordered by the vocal ligaments. 

 Arytenoids small and conical. Vocal cords : 

 L. 0'25 in. Trachea 22 rings. Voice acute. 



Mus Rattus. See details by Wolff. 



EDENTATA. Ornithorynchus paradoxus. 

 (Fig. 905.) Larynx : H. -6 in. Thyroid : wings 

 united at an obtuse angle ; body partly cartila- 

 ginous, and partly osseous ; supports laterally 

 two transverse osseous processes f f, at the 

 bases of which are two curved cartilaginous 

 appendices. Cricoid elliptical. Arytenoid 

 triangular. Ventricles not deep. A sulcus, 

 d d, lies between superior ligament and cri- 

 coid cartilage.* Epiglottis: apex acute, a. 

 Trachea 15 rings. 



Armadillo. Epiglottis bilobed. Voice mute. 



Brady pus tridaetylus or Sloth. Larynx: 

 Cart, of Santorini and superior voeal cords 

 absent. Ventricles a mere impression. Infe- 

 rior vocal ligaments free. Trachea convoluted. 

 Voice _ a plaintive melody, consisting of an 

 ascending and descending scale of tlie hexa- 

 chord.f 



PACHYDERMATA. Equus. H. 1-85. Thy- 

 roid: wings united at an acute angle, and 

 notched below to the pomum. Cricoid : 

 margins, superior deflected inwards. Crico-thy- 

 roid chink inclined both vertically and horizon- 

 tally. Arytenoids large; bases deflected from 

 each other, by which the glottis is always kept 

 open. Cart, of Santorini curved or hook-like 



* This is described by Blainville, but Meckel 

 seems not to have observed it. 

 ) Bingley, An. Biog. 



A. view of t/te internal mechanism of the Larynx oj 

 Ornithorynchus paradoxus. 



a, epiglottis ; b, superior vocal cords ; c, inferior 

 vocal cords ; d, sulcus ; /, 'transverse osseous 

 processes ; g, spines of transverse processes ; e, 

 trachea. 



triangular, a; at the base two processes* con- 

 nect it with the arytenoids. Between the com- 

 missure of vocal ligaments and epiglottis there 

 is an oval cavity, c ; and on the posterior sur- 

 face of the epiglottis a groove, furnished at its 

 base with a semihmar membrane, -f- Trachea 

 52 rings. Voice, the neigh, which is well 

 known, but not easily described. Herrissant 

 has exaggerated, as Cuvier states, the office of 

 the semilunar membrane in the production of 

 this singular sound. 



Asinus vulgaris. Larynx : H. 1 '95 in. Thy- 

 roid : wings united at an obtuse angle. Cricoid 

 elliptical. Crico-thyroid chink not large. Epi- 

 glottis : apex obtuse ( fig. 906.) ; at its base an 

 arched cavity, i, in which the vocal ligaments 

 are inserted. On each side of this cavity c, c, 

 are two circular apertures, which lead to two 

 large sacs situated behind the mucous mem- 

 brane between the vocal ligaments and inter- 

 nal surface of the thyroid. L. 1-275 in. Tra- 

 chea: rings spiral. Voice : quality discordant; 

 range about Stones. The bray is well known, j 

 Mule. Laryngeal cavities similar to those 

 in the ass. Voice, a species of bray resem- 

 bling the voice of the ass, rather than that of 

 the horse. 



* These are the horns of the epiglottis of Casse- 

 rius. 



f The semilunar membrane of Herrissant. 



j According to Herrissaut, the edge of the arched 

 cavity causes the peculiar timbre of the voice of the 

 ass, and acts like the semilunar membrane in the 

 neigh of the horse ; both these hypotheses, how- 

 ever, are extremely doubtful ; the sac mentioned in 

 the text doubtless contributes largely to the produc- 

 tion of the braying of the ass. During the bray an 

 acute sound accompanies the inspiratory movement 

 of the thorax. 



