PROF. OWEN ON THE ANATOMY OF THE INDIAN RHINOCEROS. 39 
Parr II. 
Digestive Organs. Abdominal Viscera. 
The Mouth.—The substance of both the lower and upper lip was composed of cellular 
and subligamentous tissue permeated in all directions by muscular fibres, and resembling 
in section the ‘ corpus cavernosum penis’ in the Horse: the skin covering this substance 
is very thin and vascular in the upper lip. These muscular fibres, which are homolo- 
gous with the decussating fibres in the proboscis of the Elephant, presented the striated 
characteristic of the voluntary muscular fibre under the microscope. 
The seventh pair of nerves, which was lost principally in the muscles and the above- 
described contractile tissue of the upper lip, was of large size. 
In the male Rhinoceros the tongue measured two feet three inches from the epiglottis 
to the tip, and seven and a half inches across its broad anterior part: the depth or 
thickness of the tongue is four inches, at its root. In the female Rhinoceros the tongue 
measured nineteen inches in length from the epiglottis to the tip. This organ is broad 
and flat, slightly expanded at its anterior extremity, and becoming narrower and deeper 
as it extends backwards: there is a small protuberance on the upper surface opposite the 
posterior grinders, divided by a longitudinal depression : the large fossulate papillz of the 
dorsum are principally collected in a group of ten to twelve on each of these risings: 
the epithelium is disposed on the anterior part of the tongue in a number of very fine 
close-set pointed papillz, resembling short hairs: behind the papille the epithelium is 
condensed into a thick callous stratum, which gradually becomes thinner where it covers 
the posterior glandular part of the tongue. There are no retroverted cuticular processes, 
as in the Ruminants. There is a lytta beneath the anterior flattened part of the tongue. 
A reticulate structure at the sides of the soft palate, having muciparous follicles in 
the interspaces of the meshes, and many subcompressed conical processes of various 
lengths, represents the tonsils (Pl. X. t,t, ¢): the arches of the palate, or ‘isthmus 
faucium,’ form on each side a thin sharp fold, which descends obliquely along the sides 
of the pharynx and terminates insensibly near the sides of the glottis. The soft palate 
consists of a stratum of muciparous follicles one-third of an inch thick, placed ver- 
tically between two layers of mucous membrane ; their blind extremities being in contact 
with the whitish dense membrane lining the nasal or air-passage, their orifices termi- 
nating on the soft red and vascular membrane at the roof of the mouth. The constrictors 
of the pharynx formed at the anterior margin of that canal a thick rounded edge. 
The pointed apex of the triangular epiglottis (Ib. e) curves forward above the base 
of the tongue, to which the epiglottis is attached by a pair of strong ‘ glosso-epi- 
glottidei’ muscles. 
The alimentary canal.—The cesophagus extends pretty straight from the pharynx to 
the stomach, with an uniform diameter, in its passive or contracted state, of three 
inches: its total length was five feet. It extends about six inches into the abdomen 
VOL. 1V.— PART II, H 
