In the following stages the disproportionately large size of the embryonic liver compels the colon, as the caecum descends, to assume an oblique position. When the caecal descent is completed the colon traverses the abdominal cavity in contact with the caudal surface of the liver passing from the right iliac fossa obliquely cephalad and to the left to the splenic flexure where it becomes continuous with the descending colon, which segment has early assumed its definite position in the background of the abdominal cavity on the left side (Fig. 495). This oblique position of the colon is seen in Figs. 503 and 504. During this stage the increase in the length of the colon may lead to the arrangement seen in Fig. 505, where the future transverse segment of the large intestine is bent caudad in form of an arch whose summit extends nearly to the pelvis. This condition at times persists in the adult, in cases of unusually long large intestine, and recalls the normal arrangement found in many of the cynomorphous monkeys in whom the transverse colon forms an extensive V-or U-shaped loop, with the apex directed caudad toward the pubic symphysis (Fig. 506). In other instances in the human foetus this part of the large intestine is thrown into a number of shorter irregular coils (Fig. 507). [Illustration: FIG. 503.--Human embryo, 7.6 cm. vertex-coccygeal measure. Liver and small intestine from the duodeno-jejunal to the ileo-colic junction removed. (Columbia University, Study Collection.)] [Illustration: FIG. 504.--Human foetus, 10.6 cm. vertex-coccygeal measure. Liver and greater part of small intestine removed. (Columbia University, Study Collection.)] [Illustration: FIG. 505.--Human foetus, 20.4 cm. vertex-coccygeal measure. (Columbia University, Study Collection.)] [Illustration: FIG. 506.--Abdominal viscera of _Macacus rhesus_, rhesus monkey, hardened _in situ_. (Columbia University Museum, No 1817.)] [Illustration: FIG. 507.--Abdominal viscera of human foetus at term, hardened _in situ_; hepatic flexure formed, and ascending and transverse colon differentiated. (Columbia University Museum, No. 1816.)] [Illustration: FIG. 508.--Human foetus of 10.7 cm. vertex-coccygeal measure. Liver and small intestine from the duodeno-jejunal to the ileo-colic junction removed. The colon already presents an ascending, transverse and descending segment. The appendix is retro-caecal, curved, with the tip turned down, under cover of the ileo-colic junction and mesentery. (Columbia University, Study Collection.)] Normally, however, in the process of further development and with the relative decrease in the size of the liver, the hepatic flexure (Fig. 505) becomes defined and passes cephalad and to the right, taking up the slack of the bent segment and establishing the typical ascending and transverse colon as seen in Fig. 508 (schema, Fig. 496). III. VARIATIONS OF ADULT CAECUM AND APPENDIX.