Inoculated on the rabbit, Guinea pig and mouse, it produced death with pneumonic affections (hæmorrhagic congestion or inflammation), but it failed to take in some of the rabbits and Guinea pigs. Chickens and pigs proved immune. Injected into the horse’s lung or as spray into the trachea it produced true croupous pneumonia. Fiedaler and others obtained similar results. Peter has found the fæces of pneumonic horses virulent, an important point in connection with disinfection. Schütz found that 20 grammes of the culture, in an equal quantity of boiled water, injected into the horse’s trachea, produced a rise of temperature by two or three degrees, with rigors, cough, accelerated pulse, elevated temperature, dyspnœa and prostration, but that this subsided in a few hours. By repeating this every thirty-six hours, the fourth or fifth would fail to produce a reaction and the subject proved immune. CADEAC’S DIPLOCOCCUS PNEUMONIÆ EQUINA. In the lungs of cases of contagious pleuro-pneumonia of the horse Cadeac found a round noncapsulated coccus appearing in pairs, or rarely in chains, and staining by Gram’s method. It grew slowly in bouillon and agar at 37° C., forming on the latter in twenty-four hours, a thick, whitish, oily drop, which, as it grew larger, assumed a silvery whiteness, and dried in the centre. In bouillon it precipitated a powdery sediment. The reaction of the culture medium was unchanged. It lost virulence rapidly in artificial cultures or by a heat of 50° C., and it died in ten minutes at a temperature of 60° C. Virulence was long retained when dried, or even in putrid material. This proved infecting to the ass, rabbit and Guinea pig, while the cat and white rat proved immune. Intratracheal injection of the dog produced a transient pneumonia. The ass inoculated with the blood of the infected rabbit died in three days, with a hepatized lung, pleurisy, and swarms of the microbes in the lungs, blood and internal organs. Rabbits injected intravenously had enlarged spleen, reddish exudate in the serous cavities, urine stained with hæmoglobin, and lungs and kidneys congested. With intratracheal injections the lesions were exclusively pulmonary. The pulmonary lesions were less constant in the Guinea pig. Weakened virus caused pulmonary lesions only without septicæmia. It has been suggested that this coccus is at least closely related to that of pneumo-enteritis of the horse.