This affection occurs both here and in the parenchyma of the lungs in two distinct forms, either as a circumscribed eschar on the mucous membrane, eating its way into the submucous tissue, in which it may also occur primarily, or as a diffuse gangrenous colliquescence of the bronchial mucous membrane. The conditions under which it is developed are similar to those of gangrene of the lung, with which it is sometimes combined. It generally, however, occurs in tissues in some way previously diseased, but appears rather as an accidental termination than as a necessary consequence of any peculiar local morbid process. We have seen it take its origin from inflammation of the perichondrium of the laryngeal cartilages, from tuberculous laryngeal phthisis, from typhous ulcers, and laryngeal croup, and give irise to circumscribed gangrenous destruction, or much more frequently to diffuse gangrene of the bronchial mucous membrane. In the latter case, we find a certain extent of the mucous membrane either uniformly or at certain spots, of a dirty brownish-green color, and broken up into a soft, villous, moist, friable tissue, evolving the peculiar odor of sphacelus. The tubes are filled with a corresponding, discolored, frothy, stinking, sero-ichorous fluid. It is most commonly associated with pulmonary gangrene.