Accessory causes. Infection. Experimental inoculation. Bacillus, grows on blood serum. Lesions in mouth, nose, air passages, intestines, digits. Symptoms: difficult sucking, fever, swollen, whitish spots on buccal mucosa, phagadenic sores, fœtor, symptoms of extending disease, anorexia, debility, prostration. Duration. Diagnosis from foot and mouth disease, from actinomycosis, from tuberculosis. Prevention: cleanliness, antisepsis, segregation, diet of dam, sterilized milk. Treatment: antiseptic and eliminating: locally antiseptic. This has been observed at frequent intervals in calves, as a serious, fatal, communicable disorder occurring in the first few weeks of life. _Causes._ It has been attributed to unhygienic conditions of the dams, close, damp, impure stables, unwholesome or spoiled food, and privations of various kinds, and these, in all probability, increase the susceptibility. The congestion and traumatism connected with the cutting of the teeth is another predisposing cause. The ultimate cause is, however, the contagious element and the disease has been conveyed to healthy lambs by the introduction into their mouths of the necrotic products from the diseased subjects (Dammann). Sheep inoculated in the conjunctiva presented violent conjunctivitis in forty-eight hours. Inoculated rabbits died of septicæmia. Mice showed the same symptoms as calves, while guinea pigs showed an abscess only at the seat of inoculation (Löffler). The identity of the germ has not been fully demonstrated. Dammann found a micrococcus, but testimony from the inoculation of its pure cultures is wanting, and the buccal mucosa of the sucking calf is full of varied germs some of which are irritating and pathogenic to an injured mucosa. Löffler found in the epithelial concretions (false membranes) of the mouth and intestines, a bacillus of half the thickness of the bacillus of malignant œdema, five times as long as broad and usually connected with its fellows to form filaments. He failed to obtain cultures of this in nutrient gelatine, but grew it successfully in blood serum from a calf. Transferred to fresh serum the culture failed. The pure culture does not seem to have been tried on the calf. According to Dammann the lesions occur indiscriminately in the mouth, the nose, the larynx, trachea, lungs, the intestinal canal and the interdigital space. It has been suggested that the mouth of the calf rendered susceptible by the congestion caused by suction, is infected by licking the previously infected umbilicus.