Source: Two strains were isolated from human feces. Habitat: Probably the intestinal canals of mammals. 4. Sphaerophorus siccus (Eggerth and Gagnon, 1933) Prevot, 1938. [Bacteroides siccus Eggerth and Gagnon, Jour. Bact., 25, 1933, 410; Prevot, Ann. Inst. Past., 60, 1938, 299.) sic'cus. L. adj. siccus dry. Short, thick rods about 1.0 micron long; in glucose broth the cells are coccoid and often grow in short chains. N on -motile. Gram-negative. Gelatin: No liquefaction. Blood agar colonies: Elevated, dry, diffi- cult to emulsify, 1.0 to 1.5 mm in diameter. Broth: Growth occurs as a powdery sedi- ment with a clear supernatant fluid. Indole not produced. Hj'drogen sulfide is produced. Milk: Unchanged. Acid but no gas from fructose. No acid or gas from glucose, glycerol, mannitol, sor- bitol, arabinose, salicin, trehalose, amygda- lin, cellobiose, glycogen, rhamnose, xylose or lactose. Nitrites not produced from nitrates. Anaerobic. Non-pathogenic for white mice or rabbits. Distinctive characters: Gas is produced in small amounts from peptone. Phenol red and brom cresol purple are decolorized in meat infusion broth. Source: Two strains were isolated from human feces. Habitat : Probably the intestinal canals of mammals. 5. Sphaerophorus necroticus (Nati- velle, 1936) Prevot, 1938. {Bacillus necroticus Nativelle, 1936, see Weinberg et al., Les Microbes Ana6robies, 1937, 693; Pr6vot, Ann. Inst. Past., 60, 1938, 298.) ne.cro'ti.cus. Gr. noun necrus a dead body; M.L. adj. necroticus necrotic. Short, thin, irregular rods, with a few long forms, some showing bipolar staining in young cultures. In 10 to 18 hours, central, deep-staining, ovoid swellings appear in the rods; these are not spores. After 24 hours to several days, the rods disappear, and only amorphous elements remain. Non-motile. Gram-negative. Gelatin: No liquefaction. Agar: Deep colonies small, lenticular. Gas is produced. Glucose broth: Diffuse growth which settles as a heavy, sticky deposit. Gas and fetid odor. Milk: No acid, coagulation or peptoniza- tion. Coagulated egg white not liquefied. Indole is produced. Acid from glucose, fructose, lactose, su- crose, galactose and maltose. No acid from mannitol, dextrin, inulin, amygdalin, sali- cin, arabinose or glycerol. Anaerobic. Optimum temperature, 37° C. Pathogenicity: Slightly pathogenic in pure culture. Pathogenicity more marked if mixed with Escherichia coli. Source: One strain was isolated from a case of gangrenous appendicitis. Habitat: Presumably found in necrotic tissues of man. 6. Sphaerophorus necrogenes (Wein- berg et al., 1937) Prevot, 1938. (Bacillus, Kawamura, Jour. Jap. Soc. Vet. Sci., 5, 1926, 22; Bacillus necrogenes Weinberg et al., Les Microbes Ana^robies, 1937, 681; Prevot, Ann. Inst. Past., 60, 1938, 298.) ne.cro'ge.nes. Gr. adj. necrus dead; Gr. V. gennaio to produce; M.L. adj. necrogenes necrosis-producing. Rods and very long filaments (50 to 100 microns) with swellings. Non-motile. Gram- negative. Gas is produced. Serum and ascitic fluid may or may not favor growth. Gelatin: No liquefaction. Good growth; gas. Serum agar colonies: Small, whitish, ap- pearing in 2 or 3 days; slight gas. Glucose agar colonies: Small, whitish; less growth than on serum agar. Agar stab: Small, punctiform colonies; gas. Glucose bouillon: Turbid; gas; sediment and then clarification. Liver broth: Abundant growth; gas; gray-
