_Causes._ It has been long attributed to the causes which produce other forms of enteritis and indigestions, as youth, rich stimulating feeding, sudden change to green food in spring, sudden chills, over-fatigue, confinement indoors, and prolonged costiveness. In man it is found as a sequel of infectious diseases (pneumonia, pyæmia), in Bright’s disease, cirrhosis of the liver and cancer, and in poisoning by lead, mercury or arsenic (Osler). Cadeac, who found great numbers of streptococci in the false membranes in animals, is certain it is a microbian disease, and this is doubtless true, if qualified by the statement that the microbe as is so often the case with other intestinal affections, requires an occasion in the form of a diseased or debilitated condition of the mucosa to enable it to become pathogenic. The disease is not known to propagate itself indefinitely or without such a predisposing occasion. _Symptoms._ There are dullness, prostration, langor, hyperthermia, accelerated pulse, and colics which may be slight or very severe. In some cases nervous symptoms have been observed, such as irritability or stupor and somnolence with icterus and fœtid stools. The fæces are usually semi-liquid, implying an excessive liquid secretion as well as the exudation of the membranous matter. _Lesions._ There is a pink congestion of the intestinal mucosa more or less generally distributed. Whitish false membranes cover patches chiefly on the terminal portion of the small intestine, but frequently also on the cæcum and colon, covering an especially red and angry mucosa. They may occur as simple patches, as ribbon shaped pieces, or as hollow cylinders lining the entire circumference of the intestine. They appear as if fibrillated, but contain abundance of granular matter and seem to be composed mainly of mucus with albuminoid matter and probably a little fibrine. The deeper layers, in contact with the inflamed surface are soft and gelatinoid. It is alleged that coexisting wounds on other parts of the body become covered by a soft pultaceous false membrane. _Diagnosis_ is based on the presence of the false membranes of a considerable thickness, so that they can be distinguished from the film of mucus which covers the fæcal balls in constipation or enteric catarrh. _Treatment._ Facilitate the secretion from the mucosa, and the separation of the false membrane by giving 1 lb. Glauber salts, or give this agent in doses of 5 or 6 ozs. per day. Calomel 1 dr. may be used instead and has the additional advantage of acting as a disinfectant. The alkaline carbonates or tartrates or even olive or castor oil may be used as substitutes. Antiferments like salol, naphthol, salicylic acid, and salicylate of soda have been prescribed to check the multiplication of the germ. Flaxseed tea, elm bark, and other mucilaginous agents may also be given. An easily digestible and laxative diet and a course of bitters may follow.