Three main divisions of the convolutions of the small intestine can be made out, slightly separated from each other in the figure to exhibit the caecum between them. The proximal (jejunal) set of these convolutions occupy the upper and left part of the abdominal cavity. They are the product of the single larger coil which in the earlier stage (Fig. 497, schema Fig. 490) appeared dorsad of the caecal diverticulum. The distal (ileal) division of small intestinal convolutions has become greatly augmented and lies to the right of the caecum. The concavity of the pouch is still, as in the earlier stages, directed to the right and the entrance of ileum into colon takes place from right to left. The caudal part of the abdominal cavity is occupied by an intermediate set of transition convolutions which join the proximal and distal divisions. In the two stages just described (Figs. 497 and 498, Schema Figs. 490 and 491), the initial step in the intestinal rotation has been taken, _i. e._, the beginning of the colon has been displaced cephalad from its original position in the caudal and left part of the abdominal cavity by the pressure of the rapidly growing coils of the small intestine and now lies transversely ventrad of the duodenum, having crossed the duodeno-colic neck or isthmus of the primitive umbilical loop (cf. Fig. 487, _C_). At first the distal coils of the small intestine occupy a position _behind_ as well as to the right of the caecum, forming a dorsal retro-caecal division connected by intermediate convolutions with the ventral division occupying the lower and left portion of the abdominal cavity. The apex of the caecum is frequently imbedded among these terminal coils of the ileum. With the continued growth of the small intestines a further displacement of the caecum cephalad and to the right takes place, while at the same time the terminal ileal coils pass downwards and to the left, from a retro-caecal into a subcaecal position, thus permitting a direct apposition of the caecum to the dorsal parietal (prerenal) peritoneum. The last steps in this process of withdrawal of the original voluminous dorsal (retro-caecal) division of ileal convolutions are well seen in the preparation shown in Fig. 499, taken from an embryo of 6.7 cm. vertex-coccygeal measure, and corresponding to the schematic stages represented in Figs. 490 and 491. The caecum in this preparation has not yet completed its rotation and still turns its concavity upwards and to the right, with the apex imbedded among the terminal convolutions of the ileum.