_Symptoms._ There are the usual symptoms of indisposition to suck, salivation, redness of the buccal mucosa, and general indisposition. In two or three days the mucosa shows raised, pulpy, white or grayish patches about a line in diameter. These gradually soften and break down and in four or five days leave dark red angry sores one-sixth to one-third inch in diameter dotted with grayish points and surrounded by a congested areola. These exhale an offensive odor and tend to extend in superficial area and in depth, invading indiscriminately the various subjacent tissues. The lips may be perforated, the muscles, cartilages, periosteum, and periodontal membrane invaded, the teeth may be shed, and the alveoli filled with the offensive debris of ulceration. Swelling of the throat may follow from implication of the pharynx and its lymph glands, symptoms of laryngitis, bronchitis, and pneumonia may succeed, also infective gastritis and enteritis. These various parts may be infected by the direct transference of the infecting saliva, but the germ is also held to be transmitted through the blood to implicate distant organs. Appetite is gradually lost, a blackish, fœtid diarrhœa, sets in and the calf is sunk in a profound prostration and debility due partly to the enforced abstinence and colliquative diarrhœa, but much more to the absorption of toxic matters. Death may ensue from the sixth to the twelfth day. In case of recovery a month may be requisite for the completion of convalescence. _Diagnosis._ This has to be distinguished especially from aphthous fever by the absence of the large, and clearly defined vesicles of that disease, by the fact that the mammary region and interdigital spaces usually escape, and especially by the immunity of the dam and of other more mature animals. From actinomycosis of the tongue it is diagnosed by its more rapid progress, by the marked constitutional depression, and prostration, and by the absence of the marked induration of the actinomycotic organ (holzzunge) and by the sulphur yellow pin head-like nodules of actinomyces. Tuberculosis is rare in the first weeks after birth in calves, and never makes the rapid progress nor causes the profound depression of this disorder.