with rounded ends, not in chains. Motile. Gram-positive. Spores, 0.8 to 1.0 by 1.3 to 1.5 microns, ellipsoidal, central to terminal; spore wall thick and easily stained (sporulation vari- able on most media; best on potato). Sporangia definitely swollen; spindle- shaped to clavate. Gelatin agar streak plate: Visible zone of hydrolysis. Glucose agar colonies: Small, round, smooth, dense, orange to colorless. Agar slants: Growth scant to fair, fiat, smooth, translucent to opaque, pink to orange or brownish, rapidly dissociating to the colorless stage. Glucose agar slants: Growth heavier than on agar. Many needle-, boat- and bayonet- shaped microcrystals are present in the growth after 6 days. Soybean agar slants: Growth scant to fair, pink to orange, rapidly dissociating to the colorless stage. Many microcrystals. Tyrosine agar slants: Same as on agar. Broth: Poor to fair uniform turbidity. NaCl broth: Growth in 5 per cent NaCl. No growth in 8 per cent. Milk agar streak plate: Wide zone of hy- drolysis of the casein. Potato: Growth moderate, spreading, thin, orange (sporulation and pigment for- mation may be maintained by transferring every 2 months on potato plugs; incubation temperature, 37° C; storage at 28° C.). Indole not produced. Acid but no gas (with agar as the base medium) from glucose, glycerol and man- nitol. No acid (no growth) with ammonium salts as source of nitrogen. Starch not hydrolyzed. Acetylmethylcarbinol not produced. pH of glucose broth cultures is 5.0 to 5.8. Citrates not utilized. Methylene blue usually reduced and re- oxidized. Nitrites produced from nitrates. No gas produced in nitrate broth under anaerobic conditions. Urease not produced. Aerobic, facultatively anaerobic. Growth in glucose broth under anaerobic conditions, pH 5.2 to 5.6. Temperature relations: Optimum, about 37° C. Maximum, 45° C. No growth at 50° C. Poor growth and less pigmentation at 28° C. Pathogenicity: Possible cause of death of honej^ bee larvae. Source : Isolated from dry, powdery, light- brown scales of dead larvae of the honey bee. Habitat: Probably same as the source. 19. Bacillus brevis Migula, 1900, emend. Ford, 1916. (Bacillus No. I, Fliigge, Ztschr. f. Hyg., 17, 1894, 294; Bacilhis lacHs No. I, Kruse, in Fliigge, Die Mikroorganismen, 3 Aufl., 2, 1896, 208; Migula, Syst. d. Bakt., 2, 1900, 583; not Bacillus brevis Lustig, Diag- nostica dei batteri delle acque, Torino, 1890, 52; Ford, Jour. Bact., 1, 1916, 522.) bre'vis. L. adj. brevis short. Rods, 0.6 to 0.9 by 1.5 to 4.0 microns, with ends poorly rounded or pointed, not in chains. Protoplasm finely granular. Motile. Gram- variable, usually Gram-negative. Variations: Slightly smaller or larger in diameter. Rarely encapsulated. Spores, 1.0 to 1.3 by 1.3 to 2.0 microns, ellipsoidal, central to sub-terminal. Spore wall usually thick and easily stained. Var- iation: Spores lateral in few cases, like those of Bacillus later os-porus. Sporulation in some strains poor on media made with highly refined agar; much better when crude agar is used or when soil extract is added to the refined agar (Smith and Gordon, unpublished data). Sporangia definitely bulged; spindle- shaped to clavate. Gelatin stab: Slow, crateriform liquefac- tion. Gelatin agar streak plate: Wide zone of hydrolysis. Agar colonies: Thin, smooth, translucent, quickly spreading over entire plate. Varia- tions: Small, round, opaque, non-spreading. Agar slants : Growth thin, smooth, spread- ing or non-spreading, translucent, becoming opaque and creamy with age. Glucose agar slants: Growth usually more abundant than on agar, wrinkled, spreading. Soybean agar slants: Growth usually abundant, dense, spreading. Broth: Turbidity usually heavy, uniform, with or without fragile pellicle.
