Definition. Synonym. Bacillus pestis suis, 0.8–1.5μ, nonmotile. Pathogenesis. Accessory causes, as in hog cholera: less vitality than in virus of hog cholera, bacillus in apparently healthy, deadly to birds and rodents. Lesions: like as in hæmorrhagic septicæmia, lungs suffer more than bowels, lymph glands swollen hæmorrhagic, liver and spleen may seem almost normal, bowels slightly congested, marked emaciation. Symptoms: Acute cases like hog cholera, shorter incubation—1 day, troubled breathing when driven, cough, congested petechiated skin, hyperthermia, costiveness followed by diarrhœa. Diagnosis: constancy and predominance of lung lesions and symptoms, nonmotile bacillus with polar staining, not gasogenic with glucose, very fatal to birds and rodents. Prevention: as in hog cholera. Immunization. Treatment: as in hog cholera dangerous. Serum-therapy. _Definition._ A contagious bacteridian disease of swine, acute or subacute, characterized by a short incubation, hyperthermia, marked congestion of the mucosæ, petechiæ and circumscribed blood extravasations in the skin, subcutis, mucosæ, submucosæ, and tissues, swelling, congestion and petechiation of the lymph glands, and a marked tendency to inflammatory localization in the lungs. _Synonyms._ Th. Smith identifies this affection with the “Schweineseuche” of Germany. _Bacteriology. The bacillus of Swine Plague_ (_B. Pestis Suis_) has already been described in the differential table of allied bacteria given under hog cholera. It is a short rod, with rounded ends, 0.8 to 1.5μ. × 0.6 to 0.8μ, staining readily in aqueous basic aniline colors and bleaching in Gram’s iodine solution. The staining is distinctly polar, the colored portions being more or less crescentic with the concave or straight border turned inward toward the central clear space. It is destitute of flagella and distinctly nonmotile unlike the very active bacillus of hog cholera. It further differs in its growth on potato which is slight, gray and waxy. On gelatine, too, it gives a feeble growth (or none) unlike the brownish colonies of the bacillus of hog cholera. It fails to liquefy gelatin. On agar the growth is more active, being grayish, translucent or brown. Those forming under the surface are like flat horizontal discs with a small microscopic elevation or knob in the center. It grows in milk producing little or no acid and no clot. It produces gas with none of the sugars—glucose, lactose, saccharose—in contrast with the gas production in glucose by the hog cholera bacillus. It shows much less vitality and hardihood than the hog cholera bacillus, growing but feebly between 65° and 70° F., and most actively at 97° to 100° F.; dying in 7 minutes at a temperature of 58° (moist); dying in 3 days when dried, in 4 to 6 days in the soil, in 10 to 15 days in water and instantly in 0.04 per cent solution of lime water.