I. The shortness of the large intestine in the cat will require careful manipulation in order to produce a disposition in conformity with the arrangement of this portion of the human intestinal tract. By stretching the gut somewhat and pulling it well out of the pelvis sufficient length will be obtained to establish an ascending, transverse and descending colon. Move the caecum from the subhepatic position which it occupies immediately after rotation (Fig. 145) down to the lower and right-hand corner of the abdomen. Pull the distal portion of the large intestine well out of the pelvis and obtain thus sufficient length to establish an ascending, transverse and descending division each provided with a free mesocolon (Fig. 146). In the formation of the three definite main segments of the human large intestine, ascending, transverse and descending colon, the following stages may be recognized: [Illustration: FIG. 146.--Abdominal viscera of cat, with the intestines rotated to correspond to the adult human disposition, with ascending, transverse, and descending segments of the colon. (From a fresh dissection.)] 1. Immediately after rotation the large intestine lies transversely along the greater curvature of the stomach, with the caecum on the right side in front of the duodenum and closely applied to the caudal surface of the right lobe of the liver (Fig. 147). [Illustration: FIG. 147.--Human foetus, 6.6 cm., vertex-coccygeal measure; liver removed. (Columbia University Museum, Study Collection.) x 4.] PERSISTENCE OF SUBHEPATIC POSITION OF CAECUM IN ADULT.--The period at which the caecum descends into the iliac fossa is liable to a considerable range of variation. Treves found in two foetus, measuring respectively 41/2" and 51/2", the caecum on a level with the caudal end of the right kidney, while in several individuals at full term the caput coli was still placed immediately below the liver, with no large intestine in the place of the ascending colon. This condition is well illustrated in the foetus shown in Fig. 124. The caecum may remain undescended throughout life. Treves, in an examination of 100 bodies, found this condition in two subjects, both females, one 41, the other 74 years of age. Both cases presented an identical disposition. There was no large intestine in the place of the ascending colon. The caecum was placed on the right side, immediately underneath the liver, just to the right of the gall-bladder; it was quite horizontal in position, continuing the long axis of the transverse colon and included between the layers of the transverse mesocolon. From the extremity of the caecum a horizontal fold was continued to the abdominal parietes and upon it the edge of the liver rested. In one of these instances the colon from the tip of the caecum to the splenic flexure measured 38". The great omentum was attached only to the left half of this portion. The descending colon was very long, measuring 15".