_Typhus ulcers._ In continued fevers where the disease especially attacks the intestines, we find an ulceration of Peyer’s patches and the solitary glands, which is called _typhus ulceration_ by Rokitansky, and is thus described by him:—“After a preceding hyperæmia around the solitary follicles, and in and around Peyer’s patches, there is an enlargement of the glandular structures, followed by a softening and breaking down of the glandular mass. The cavity remaining on the mucous membrane after the discharge of this mass constitutes the typhus ulcer. Its form is elliptical, if a large patch has been destroyed; round, if a smaller patch or a solitary gland has been destroyed. Partial destruction of a patch will produce an ulcer of irregular shape. The size varies also, according to the amount of ulceration.” The margin of the ulcer is invariably formed by a well defined fringe of mucous membrane, which is a line or more wide, detached, freely movable, of a bluish-red, and subsequently of a slaty or blackish-blue color. The base of the ulcer is formed by a delicate layer of submucous tissue, which covers the muscular coat. The lower third of the small intestine is most liable to be involved in the ulcerative process, the number and size of the ulcers increasing as they advance toward the ileo-cœcal valve. _Dysentery_ may also produce extensive ulceration of the colon, with considerable loss of substance. This loss may be repaired by cicatrization. In some cases, the cicatrix tissue, condensed into fibrous bands, forms projections into the cavity of the intestine, and not unfrequently encroaches upon its calibre in the shape of valvular or annular folds, giving rise to stricture of the colon. =Dilatation.= Disease of the nervous centres, inflammation of its serous tissue, or simple atony of the muscular fibres, may be the cause of inaction of the intestine and consequent distension. Stricture will also produce distension above itself, by an accumulation of the contents of the intestine. In these latter cases, the dilatation is often enormous. =Contraction= of the intestines may occur throughout a considerable extent, or in a very small part. In the former case, it results from the canal having been for some time empty, and is most likely to occur below a stricture. It can hardly be considered in itself a morbid condition. The second kind of contraction or constriction, is generally morbid, and may result either from external pressure by tumor or otherwise, or from a disease of the tissue itself. The cicatrices of ulcers which have assumed an annular shape, are the most frequent causes of stricture originating in the intestine itself. =Displacements.= The most common of these constitute the various forms of hernia. 1. _Inguinal Hernia._ Here the intestines escape by the inguinal canal, and it is _Scrotal_ in man, when they descend into the scrotum, and _Pudendal_ or _Vulvar_ in woman, when into the labia majora.