The caecum and the vermicular process are occasionally absent, or are only imperfectly developed; in some cases the former has been found fissured (Fleischmann).

Anomalies in the position of the caecum are confined to its position on the left side in lateral dislocation of the abdominal viscera, and to its position in large inguinal or umbilical hernia. Its attachments are sometimes very loose, and this appears to result from repeated dilatation.

Catarrhal inflammation of the caecal mucous membrane is remarkable on account of the frequency of its occurrence, and that form which is occasioned by habitual constipation, so-called typhlitis stercoralis, is peculiarly characteristic. It chiefly originates in sedentary habits, indigestible food, and rheumatism of the muscular coat. The symptoms are those of catarrhal inflammation generally; it runs an acute course, is subject to frequent relapses and degenerates into the chronic form. Removal of the accumulated pus, and avoidance of fresh accumulations, generally suffice to establish a cure. If this is not effected, ulcerative destruction of the mucous membrane, and continued sinuous suppuration of the muscular coat, result. In this manner rapid perforation of the intestinal parietes, and especially of the posterior side, may follow, either inducing extensive inflammation, ichorous destruction of the cellular tissue in the iliac and lumbar regions and death; or giving rise to general peritonitis, in consequence of the destructive process passing from the right iliac region in a different direction.

In the chronic form the cellular tissue at the posterior surface of the intestine condenses, and the adjoining muscular coat and the entire caecum shrivel up; on cessation of the ulcerative process, the caecum is found converted into a slate-colored capsule, with dense parietes, of the size of a walnut or a pigeon's egg; in the place of the-mucous membrane there is a sero-fibrous, retiform and trabecular tissue.

In reference to the caecum we observe, that the inflammation of the loose, stringy, cellular tissue external to the iliac fascia (perityphlitis), is of considerable importance. It is occasionally idiopathic, but more frequently metastatic; it is very dangerous, both on account of the facility with which the pus spreads, and on account of the perforation of the caecal parietes which may ensue, and the consequent extravasation of intestinal contents into the seat of inflammation.

The vermicular process is sometimes reduced to a mere cellular sinus" of the caecum; it varies in size from that of an insignificant nodule to five or six inches.

There are considerable variations in the position of the caecum.

Adhesions of its free extremity may become a matter of importance forming rings or fissures in which the intestine is strangulated.

Catarrhal inflammation of the vermicular process is a disease of common occurrence, and very dangerous on account of its consequences. It much resembles typhlitis stercoralis, and is invariably the result of faecal matters and foreign bodies, especially small fruit-stones, having become lodged and hardened in it.

The affection has a torpid character, may exist for a long period as blennorrhcea, and is accompanied by thickening of the coat of the vermicular process. After frequent exacerbations it passes into ulceration, which may, if the foreign body remains loose, attack the entire process, or if the former becomes fixed, affect only the point of attachment, or the vermicular process. In the second case, the constant irritation at one spot, or the accumulation of ulcerative secretion and the consequent distension, induce a rapid development of the morbid process.

Under favorable circumstances, especially if the foreign body is discharged, the ulceration terminates, and the vermicular process partially or entirely shrivels up and forms a lead- or slate-colored ligamentous appendix.

In the opposite case the ulceration, especially when gangrene is superinduced, more or less speedily brings on perforation of the vermicular process; this may occur at various points, sometimes at or near the termination, sometimes at the circumference, in such a manner as to cause a division into two parts. This perforation and the consequent discharge of the purulent contents into the peritoneal cavity, are not immediately followed by general peritonitis, inasmuch as the previous irritation has induced adhesions with the neighboring peritoneal folds, which render the ultimate perforation innocucous for a time, as far as regards the remainder of the peritoneum. In the interior of the circumscribed cavity the ulcerative process in the mean while continues, the adhesions gradually give way, and general peritonitis ensues.

We further occasionally observe a metamorphosis of the vermicular process produced by obturation, which is analogous to dropsy of the efferent ducts of glands, and which is most apparent in the gall-bladder (hydrops cystidis felleae). The foreign body sometimes attaches itself to a certain point and closes the canal without inducing ulceration; in consequence of an accumulation of the mucous secretion the vermicular process dilates, the mucous membrane thins and is gradually converted into a serous membrane which secretes an albuminous fluid. The vermicular process is thus metamorphosed into an hydropic capsule, which in the course of time certainly may become the seat of inflammation, resulting in ulceration and perforation.

Typhous and tuberculosis affections frequently extend to the vermicular process, and both may be followed by perforation.