296 THE ANATOMY OF THE HORSE. 



medium size it measures about three feet in length, and when moderately 

 distended it has a capacity of about four gallons. At one of its extremi- 

 ties it is curved, forming what is termed the crook of the cacum, while 

 the opposite extremity tapers to a blind point, from which the bowel is 

 named. The bowel has a puckered appearance, which is most evident 

 when it is distended. This is owing to the longitudinal muscular fibres 

 of its wall being not unifonnly distributed as they are in the small intes- 

 tine, but collected into bands, which shorten the bowel by throwing it 

 into folds. The terminal portion of the ileum (small intestine) joins the 

 caecum on the concave side of the crook, and a few inches above the 

 point of conmaunication is the orifice by which alimentary matters arc 

 passed on to the colon. The crook of the caecum is fixed in the right 

 sublumbar region by means of loose cellular tissue, and it is in contact 

 with the right kidney and the pancreas. On its inner side it adheres by 

 cellular tissue to the termination of the doiible colon, and the duodenum 

 passes round it on the outer side. The remaining portion of the bowel 

 extends do^\^l wards and forwards through the right hypochondriac region, 

 terminating by its blind point in the epigastri\un. The first portion of 

 the large colon, which lies to its inner side, extends in the same direction, 

 and the peritoneum in passing from the one bowel to the other forms a 

 fold which has been termed the meso-ccecum. As the caecum is not 

 adherent to the abdominal parietes except in the neighbourhood of its 

 crook, it admits of some displacement ; and the student must therefore 

 be prepared to find it deviating somewhat from the course just 

 described. 



The Double or Large Colon. This bowel is termed double because 

 when taken out of the abdomen it is aiTanged in the form of two paral- 

 lel portions; but in order that it may be accommodated within the 

 cavity, it has again to be doubled, so that in its natural disposition it 

 presents four portions, which receive numerical designations. In an 

 animal of medium size its length is about ten feet, and its capacity 

 about sixteen gallons. It is p\ickered like the caecum, and from the 

 same cause. 



The 1st division of the bowel begins at the crook of the caecum, by 

 an orifice of commiuiication which is comparatively small. It extends 

 downwards and forwards through the right hypochondriac region, b\ilg- 

 ing laterally into the umbilical region ; and on reaching the epigastrium, 

 the bowel becomes bent on itself, forming what is termed, from its relation 

 to the ensiform cartilage of the sternum, the suprastei-nal flexure. The 

 angle of this flexure forms the point of separation between the 1st 

 and 2nd portions of the double colon. 



The 2nd division, beginning at the suprasternal flexure, runs back- 

 wards on the left side of the abdomen, occupying the hypochondriac, 

 umbilical, and lumbar regions; and on approaching the entrance of the 



