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



larger male its texture was softer and more grumous ; and it weighed 44 lbs. avoirdu- 

 pois. With respect to its form, I did not find an agreement either with the statement 

 of Mr. Thomas' or the description in the second edition of the ' Lecons d'Anatomie Com- 

 paree,' iv. p. 464 (1836). In both specimens of Rhinoceros the liver was divided into 

 fewer lobes than ordinary, taking the Mammalia generally, yet had a right lobe in addi- 

 tion to the principal bifid lobe and the left lobe, the two latter only being assigned to it 

 by Cuvier. The form of the gland is flattened, as in the hoofed animals generally ; its 

 greatest thickness was not more than six inches in the male. Its longest or transverse 

 diameter measured in the female twenty-seven inches, and the length or antero-poste- 

 rior diameter of the middle lobe seventeen inches. Three great hepatic veins join the 

 inferior cava just below the diaphragm. The strong serous tunic of the liver was 

 beautifully marked by arborescent vessels of a white colour. The ' ligamentum rotun- 

 dum ' and corresponding fold of peritoneum entered as usual into the notch dividing 

 the middle lobe, which might be compared to the cystic lobe in the quadrupeds which 

 possess a gall-bladder. This appendage, however, as in Mr. Thomas's dissection", was 

 wanting, as it is also in the other perissodactyle or odd-toed Pachyderms ; e. g. the 

 Hyrax, the Tapir, the Elephant, and the Horse. In these, as in the Rhinoceros, the 

 absence of the gall-bladder seems to be dependent on the small size of the stomach as 

 compared with the quantity of food taken, to the consequent frequency of feeding, and 

 to the rapid and probably unintermitting transit of the gastric contents through the 

 small intestines to the enormous csecal and colonic receptacles where digestion and 

 animalization are finally completed^. The great biliary duct is formed in the portal 

 fissure by the union of six or seven branches from the lobes of the liver : its diameter is 

 half an inch ; it terminates in the duodenum six inches from the pylorus. 



The pancreas resembles that of the Horse and Tapir : its principal duct (PI. XIV. 

 fig. 1, h) enters the intestine close to the biliary duct {lb. a), communicating therewith 

 in the oblique course between the tunics : the duct of the smaller portion of the 

 pancreas {lb. h) terminates about two inches from the large and protuberant common 

 opening of the preceding ducts, but at the same distance from the pylorus. 



The spleen is an elongated, subtrihedral, flattened body, lodged in the duplicatures of 

 the short omentum. It weighed 5 lbs. in the male, and 3 lbs. in the female Rhinoceros: 

 in the latter its length was two feet six inches ; its greatest breadth one foot ; its smallest 

 breadth six inches : in the male it measured three feet six inches in length, one foot 

 four inches in breadth : it resembles in structure that of the Horse. 



Kidneys. — The weight of these two glands was about 8 lbs. in the female and 1 1 lbs. 

 in the male Rhinoceros. In both they had the same situation in the abdomen as in the 

 Horse. They were lobulated, and the extent of subdivision was intermediate between 



' "It was divided into several lobes." — Tom. cit. - See also Cuvier, loc. cit. iv. p. SIO. 



' See the excellent remarks by Mr. Youatt in his work on ' The Horse," 8vo, 1831, p. 212. In the Hog the 

 caecum is comparatively small. 



