. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. S58 STOMACH AND INTESTINE. described as depressed into a fossa in this situation. The thin stratum of tissue which Fig. flan of an agminate follicle, as seen by a vertical section. Magnified 40 diameters. a, short and conical villi surrounding the follicle; b, intestinal tubes in the same situation; c, muscu- lar stratum of the mucous membrane; d, submu- cous areolar tissue, in which the follicle is chiefly situated; e, circular layer of the muscular coat; f, longitudinal layer of the same ; g, peritoneal coat; h,
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. S58 STOMACH AND INTESTINE. described as depressed into a fossa in this situation. The thin stratum of tissue which Fig. flan of an agminate follicle, as seen by a vertical section. Magnified 40 diameters. a, short and conical villi surrounding the follicle; b, intestinal tubes in the same situation; c, muscu- lar stratum of the mucous membrane; d, submu- cous areolar tissue, in which the follicle is chiefly situated; e, circular layer of the muscular coat; f, longitudinal layer of the same ; g, peritoneal coat; h, follicle enclosing nuclear contents; z, apex of the follicle projecting into the cavity of the bowel. intervenes between the follicle and the interior of the bowel (at i,jftg. 270.) is so delicate, that its exact anatomy is not easily verified by vertical sections. It appears, however, to con- sist of a very small quantity of indistinctly fibrous tissue j which encloses some capillaries, and is covered by the ordinary layer of co- lumnar epithelium. The frequent rupture of the follicle in this situation has led many to regard it as either possessing a permanent orifice here, or ac- quiring one by a kind of natural dehiscence. But later researches seem to show that this open state is quite exceptional and accidental; being due to disease, putrefaction, or mechanical violence. The author can at least express his own conviction that — as Boehm lontr airo o ~ stated, — the agminate follicles are closed sacs. This conclusion is much confirmed by the fact, that the follicles of some animals are altogether beneath the mucous membrane and the tubes, and quite distinct from both of them ; so as to lie wholly in the sub-mucous areolar tissue.* While the vascular arrange- ments which we are about to describe seem equally incompatible with any theory of their normal dehiscence. Each of these follicles essentially consists of a capsule, enclosing a number of delicate capillaries, the i
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