48 PROF. OWEN ON THE ANATOMY OF THE INDIAN RHINOCEROS. 
up by dense elastic and aponeurotic membrane, to which yielding walls of the larynx 
some of the fibres of the thyreo-arytenoidei muscles adhere. The arytenoid cartilages 
are relatively of large size; their base extends half-way across the aperture of the 
larynx, and from the anterior extremities of these produced bases, the upper 
(Pl. XV. fig. 1, w) and lower (Jb. v) ‘ chordz vocales’ extend forwards to the thyroid 
cartilage and base of the epiglottis. Only the anterior half, therefore, of the ‘rima 
glottidis’ is bounded by vibratile vocalizing material, and the ordinary feeble bleat of 
the Rhinoceros (like that of a calf) is what might be expected to be produced by such 
a structure. 
On each side, between the upper and lower chordz vocales there is the opening of a 
large sacculus laryngis, which communicates anteriorly with a crescentic fossa under 
the base of the epiglottis. A fold of membrane (Pls. X. & XV. /) extends on each side 
from a small fibro-cartilage (f), at the inner or under side of the base of the epiglottis, 
downwards, inwards, and forwards to the anterior termination of the chordz vocales, u 
and v: these oblique folds form the inner or posterior walls of the anterior fossz of the 
sacculi laryngis. 
The anterior or superior labia (Pl. XV. fig. 2, m) of the glottis form two broad, thick, 
slightly everted folds of mucous membrane. 
In the mass of muscles (Pl. XV. fig. 2, 0, 0) attached to and passing between the 
arytenoid cartilages, there are developed about twelve tendons which radiate to be 
inserted into the central sesamoid cartilage before mentioned. 
The epiglottis (Pls. X. & XV. e, e) is of a triangular figure, with the pointed apex 
curved forwards, and having strong glosso-epiglottidei muscles attached to it. 
The thyroid gland consisted of two elongate, subtriangular lobes extending from 
the sides of the larynx to the fourth tracheal ring; diminishing as they descend and 
united by a very thin and narrow strip continued between their inferior extremities, 
obliquely across the front of the trachea. The structure of this body is more distinctly 
lobular than is usually seen; a small compact yellow glandular body was attached to 
the thyroid at the point where the veins emerge. 
Part IV. 
Generative Organs. 
Male organs.—The cremaster is a very powerful muscle, and consists of coarse 
carneous fasciculi in two flattened masses, one crossing the other obliquely as they 
escape with the spermatic chord beneath the arch of the abdominal ring. A cluster of 
lymphatic glands with much tough elastic cellular tissue fill up the rest of the ring. 
The cremaster at this part measures one inch and a half in breadth and half an inch in 
thickness. 
