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



The small intestines have nearly the same disposition as in the Horse ; they are sus- 

 pended by a short mesentery, in which the anastomosing arteries form only one series of 

 arches. The raucous membrane of the ileum projects in the form of a circular fold within 

 the caecum ; but it seems inefficient as a valve for preventing regurgitation of at least 

 fluid matters from the large intestines. The length of the csecum (PI. XIII. ca) from this 

 orifice to its blind extremity in the male Rhinoceros was three feet, and its greatest cir- 

 cumference was four and a half feet. In the female Rhinoceros the length of the csecum 

 was two feet ; its circumference two feet six inches ; these proportions to the colon and 

 the rest of the intestinal canal being rather less than in the Horse. The anterior sur- 

 face of the csecum is traversed longitudinally by a fibrous band, four inches broad, upon 

 which it is slightly sacculated : a second band appears, nearer the colon. Its lining 

 membrane was puckered up into innumerable irregular small transverse rugse, which 

 appear, however, to be but temporary foldings of the mucous membrane, and are easily 

 obliterated when this is stretched. The colon for the first four feet of its extent was 

 puckered up upon three longitudinal bands into sacculi, each about five inches long : it was 

 suddenly bent upon itself at this part, forming the long and large fold {Ih. co' , co^), the 

 two parts of the fold being very closely connected to each other ; it there became dilated 

 into the very wide portion which formed the most prominent object on laying open the 

 abdomen ; the beginning of this dilated portion is also closely adherent by its posterior 

 surface to the opposite surface of the beginning of the Ctecum. The circumference of 

 this dilated part of the colon (which if permanent, and not due to accidental accumu- 

 lation of alimentary matter, might be regarded as representing a second caecum or 

 reservoir,) is five feet : beyond this fold the colon becomes gradually narrower, its 

 smallest circumference being twenty inches, where it passes into the rectum, which 

 forms several short convolutions before its termination. 



The entire length of the colon was . . 

 The entire length of the rectum ... 



The total length of the intestinal canal, including the csecum, was in the female 

 seventy-three feet ; in the male ninety-six feet, or eight times the length of the entire 

 animal. 



The circumference of the rectum was ten inches iu the female, and sixteen inches in the 

 male ; but it widens towards the anus. The masses in which the fseces are discharged 

 from the immense receptacles formed by the large intestine, are greater than in the 

 Elephant, and are softer and more amorphous. 



The longitudinal muscular fibres of the rectum were developed into such powerful 

 fasciculi as to lead me to suspect some change of tissue ; but on examining the fibre 

 microscopically, it presented the same absence of aggregation of the ultimate fibres into 

 striated bundles, as in the higher tract of the intestines. The contrast between these 



