In the early stage of peritonitis, the injected vessels give the membrane a more or less red appearance, which will be more marked in streaks and patches. From the readiness, however, with which fibrinous exudation takes place from this membrane, this redness is seldom very strongly marked, and in some instances will scarcely be noticed, unless the surface is carefully scraped, thus removing the exudation. Small extravasations of blood are occasionally found in the substance of the membrane. The muscular coat of the intestines, where the peritoneal covering is involved, may become infiltrated with serum, the fibres relaxed and paralyzed, thus permitting of the great tympanitic distension found in these cases. _Chronic peritonitis_, is not a very common occurrence. It may, however, follow an attack of acute peritonitis, and is sometimes found in connection with ascites, or tubercular deposits in the peritoneum. In examining the body of a colored woman who had died of heart disease, accompanied with general dropsy, and who had suffered abdominal pain and tenderness for a number of weeks previous to death, a large portion of the peritoneum, particularly that reflected upon the abdominal walls, was found intensely red, the blood-vessels having an arborescent arrangement, and being beautifully injected. No plastic matter was found effused upon the surfaces. The cavity contained some twelve quarts of serum. =Fibrinous Exudation=, as already observed, readily follows inflammation of this membrane. It will often be found as a uniform layer covering the whole surface of the peritoneum, rendered more apparent, however, by separating parts, when it appears as delicate bands or filaments, stretching across the interspace. In cases of acute inflammation, this plastic effusion is often very great, and frequently intermixed with purulent matter, while the serous fluid, which is poured out in considerable quantities in these cases, is rendered turbid by the presence of numerous flakes of fibrin, and quantities of pus cells diffused through the same. More or less extensive and firm adhesion of parts may thus be induced, the plastic matter effused becoming more and more firm, and finally converted into dense bands of fibrous tissue. Mechanical obstruction and strangulation of the bowels, may be induced by the presence of these bands, stretching between parts, and forming thus an opening through which the bowel passes, and finally becomes incarcerated. =Suppuration= is not an unfrequent result of acute peritonitis; the matter being found uniformly smeared over the whole surface, or, in some cases, confined to a single part, thus forming a circumscribed abscess. Adhesions having taken place around the boundaries of the suppurating surfaces, in this manner the diffusion of the matter is prevented, and its discharge into the intestinal canal, or in some instances upon the surface of the body, is promoted.