Fig. 510.—Human fœtus at term. Cæcum and ileo-colic junction; ventral view. (Columbia University, Study Collection.)

1. Appendix.
2. Reduced intermediate non-vascular fold.
3. Ventral vascular fold.

I. The crescentic curve of the cæcum is only slightly marked; the appendix arises from the most pendent part of the pouch and hangs downward (schema, Fig. 509, I, a).

This form, which is encountered only occasionally in the fœtus and infant, is illustrated by the preparation shown in Fig. 510, taken from a fœtus at term.

II. In the majority of cases the inherent crescentic shape of the cæcal pouch is pronounced and carries the termination of the funnel with the root of the appendix cephalad and to the left toward the caudal margin of the ileo-colic junction (schema, Fig. 509, II, a).

At birth this typical arrangement of the cæcum frequently places the pouch in a nearly transverse position, with the apex and the root of the appendix turned to the left, in contact with, or under cover of the terminal piece of the ileum at its junction with the large intestine.

Figs. 511 and 512 represent the parts in the ventral view in the fœtus at term.

Fig. 511.—Human fœtus at term. Cæcum and ileo-colic junction; ventral view. (Columbia University, Study Collection.) 1. Appendix, coiled spirally behind terminal ileum.
2. Non-vascular intermediate fold.
  Fig. 512.—Human fœtus at term (negro). Cæcum and ileo-colic junction; ventral view. (Columbia University Museum, No. 692.)
Fig. 513.—Human fœtus at term. Cæcum and ileo-colic junction; dorsal view. (Columbia University, Study Collection.)   Fig. 514.—Human fœtus at term. Cæcum and ileo-colic junction; dorsal view. (Columbia University Museum, No. 1715.)

Figs. 513 and 514, also taken from the fœtus at term, show the cæcum from the dorsal aspect and illustrate well the sharp character of the curve which carries the apex of the pouch up and to the left.