PROF. OWEN ON THE ANATOMY OF THE INDIAN RHINOCEROS. 39 



Part 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 papillae 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 papillae, resembling short hairs : behind the papillae tlie 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 (PI. X. t, 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 {lb. 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 oesophagus 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. IV. PART U, H 



