In the =larynx= ulceration is sometimes met with bacilli, however, have not yet been found in these ulcers. Diphtheritis of the pharynx and larynx may occur. Catarrhal or croupous pharyngitis may occur; while swelling of the follicles of the pharynx and base of the tongue is frequently noticed. =Peritonitis= is always present in fatal cases in which perforation of the bowel has taken place. The perforation may occur in ulcers from which the sloughs have already separated, or it may be caused by a necrosis of all the coats. Extensive peritonitis may occur without perforation, and is probably due to extension of the inflammation to the peritoneum. The =heart= may be affected. Endocarditis is rare, while pericarditis is much more frequent. Myocarditis is frequently met with, the cardiac muscles presenting parenchymatous and rarely hyaline degeneration. The =arteries= are frequently found to be involved. These conditions (obliterating arteritis and partial arteritis) may affect the smaller vessels, especially those of the heart, but more commonly affect the arteries of the lower extremities. Thrombosis of the veins, especially of the femoral, and more rarely of the cerebral veins and sinuses, occurs. Granular and hyaline changes in the voluntary =muscles= may occur. This degeneration does not affect the whole muscle but involves only certain fibres. Regeneration takes place during convalescence. With the nervous system meningitis is rare. The peripheral =nerves= are frequently the seat of parenchymatous changes. The ganglia of the trunks of the vagi present an inflammatory change. The =blood= presents little change. During the first two weeks the red corpuscles gradually decrease in number until the first week of convalescence, after which they gradually increase in number. There is often a marked decrease in the number of leucocytes. Leucocytosis is absent. The hemoglobin is always reduced. =Symptoms and Course.=—The incubation period varies from a few days to two weeks or longer. During this time the patient may feel in his usual health, but more often there is a feeling of languor and indisposition to exertion, loss of appetite, slight coating of the tongue, nausea, headache, chilliness, but seldom a decided rigor, pains in the back or legs and nose-bleeding. Any of these symptoms may be present and last usually from a few days to a week or more. These symptoms increase in severity and the patient takes to his bed. The invasion as a rule is gradual.