nose. No acid from xylose or mannitol. With organic basal medium (Proom and Knight), acid from arabinose and xylose. Starch hydrolyzed. Crystalline dextrins not produced from starch. Acetylmethylcarbinol not produced. pH of glucose broth cultures is 5.8 to 6.0. Citrate utilization variable. Methylene blue reduction variable. Nitrites may or may not be produced from nitrates. Usually no gas produced in nitrate broth under anaerobic conditions. Urease not produced. Pantothenic acid, biotin and thiamine are essential for growth. Lecithinase reaction positive though re- stricted. Aerobic, facultatively anaerobic. Scant growth in glucose broth under anaerobic conditions, pH 5.4 to 6.4. Temperature relations: Optimum, be- tween 33° and 40° C. Maximum, between 45° and 50° C. Slow growth at 28° C. Source: Isolated from soils of Southern England. Habitat: Probably widely distributed in soil. 24. Bacillus sphaericus Neide, 1904. (Cent. f. Bakt., II Abt., 12, 1904, 350.) sphae'ri.cus. Gr. adj. sphaericus spherical. Rods, 0.6 to 1.0 by 1.0 to 7.0 microns, with ends rounded or pointed, occurring singly or in short chains. Motile. Gram-variable, often Gram-negative with Gram-positive granules. Spores, 0.7 to 1.2 microns in diameter, round, terminal to subterminal. Spore wall usually thick and easily stained. Remnants of the sporangium often adhere making the surface rough and spiny. Immature spores sometimes ellipsoidal, becoming round. Sporulation variable, best on soybean agar. Sporangia, definitely swollen; usually drumstick-shaped. Gelatin stab: Growth scant; no liquefac- tion. Gelatin agar streak plate: Usually there is a visible zone of hydrolysis. Agar colonies: Thin, smooth, translucent, rapidly spreading over entire plate. Varia- tions: Small, round or irregular. Giant agar colonies: Usually motile mi- cro-colonies of various shapes move in large arcs from the point of inoculation and cover the plate in 1 day (the surface of poured agar plates should be dried by holding at room temperature for 2 or 3 days before use) . Agar slants: Growth thin, smooth, trans- lucent, spreading. Variations: Rough, re- stricted, opaque, wrinkled. Agar slants at pH 6.0: Growth same as at pH 7.0. Glucose agar slants : Same as on agar. Glucose nitrate agar slants: Scant, if any, growth. Soybean agar slants: Growth heavier and sporulation much better than on agar. Broth: Turbidity heavy, uniform to gran- ular. Sometimes a fragile pellicle is formed. NaCl broth: Usually there is growth in 4 per cent NaCl. No growth in higher con- centrations. Milk: No change. Milk agar streak plate: Hydrolysis of the casein is variable. Potato: Growth thin, soft, spreading, gray, usually becoming brownish with age. ^Indole not produced. — No acid from carbohydrates. ^Starch not hydrolyzed. Acetylmethylcarbinol not produced. pH of glucose broth cultures is 7.8 to 8.2. Citrates usually not utilized. Methylene blue reduced; not reoxidized in 21 days. Nitrites not produced from nitrates. No gas produced in nitrate broth under ana- erobic conditions. Urease production variable. Usually thiamine and sometimes also biotin are essential for growth. Lecithinase not produced. Aerobic. No growth in glucose broth under anaerobic conditions. A Temperature relations: Optimum, be- tween 28° and 35° C. Maximum, between 40° and 45° C. Not pathogenic for guinea pigs. Source: Isolated from mud from a pond; also from rotting cypress and oak wood and soil. Habitat: Widely distributed in nature. 25. Bacillus pasteurii (Miquel, 1889) Migula, 1900. {Urobacilhis ■pasteurii Miquel,
