dull luster, a contoured surface, a butyrous consistency and an odor of butyl alcohol. Milk: Acid and gas; slight coagulation, no peptonization. Litmus milk: Acid, gas, coagulation, re- duction in bottom of tube; no digestion. Potato slant: No visible growth, but a butyl alcohol odor, as well as gas, is present in the substended liquid. Broth: No growth. Indole not produced. Hydrogen sulfide not produced. Acid and gas from glucose, sucrose, lac- tose, maltose, inulin, starch, salicin, dex- trin, mannitol and galactose. Glycerol is not fermented. Nitrites not produced from nitrates. Optimum temperature, between 28° and 33° C. Anaerobic. Source: Isolated from an ear of sugar maize. Habitat: Probably soil. 15. Clostridium ainylolyticuin Prevot and Saissac, 1950. (Ann. Inst. Past., 79, 1950, 331.) a.my.lo.ly'ti.cum. Gr. noun amylum fine meal, starch; Gr. adj. lyticus loosening, dis- solving; M.L. adj. amylolyticus starch-dis- solving. Straight rods, 0.8 to 1.0 by 4.0 to 5.0 mi- crons. Spores ovoid and subterminal, swell- ing the cells. Motile. Strongly Gram-posi- tive. Non-fetid gas and a pronounced butyric odor are produced in culture media. Gelatin: No liquefaction. Bean or potato agar deep colonies: Small, woolly, irregular, white, opaque. Gas is produced. Milk: Acid coagulation without retraction or digestion of clot. VF glucose (or without glucose) broth: No growth. Peptone solution (2 per cent) : No growth in autoclaved medium; in filtered broth, growth abundant. •Potato mash: Growth rapid, abundant, very gaseous, acidified (pH 4.5 after 4 days of incubation). Very pronounced butyric odor. Mash disintegrated, liquefied, ropy. Indole not produced. Hydrogen sulfide not produced. Spontaneously, only starch and lactose are fermented; pectin not fermented. The following carbohydrates are fermented (tested in filtered peptone solution) : glu- cose, fructose, galactose, maltose, sucrose and mannitol. Nitrites produced from nitrates in the presence of starch. Sulfites reduced slowly only in the pres- ence of starch. Coagulated proteins not attacked. Anaerobic. Optimum temperature, between 33° and 37° C. Hemolysin not produced. Toxin not produced. Not pathogenic for guinea pigs or mice. Source: Isolated from soil. Habitat: Presumably soil. 16. Clostridium nigrificans Werkman and Weaver, 1927. (Werkman and Weaver, Iowa State Coll. Jour. Sci., 2, 1927-28, 63; also see Werkman, Iowa State Coll. Re- search Bull. 117, 1929, 165.) nig. ri'fi. cans. L. part. adj. nigrificans blackening. Rods, 0.3 to 0.5 by 3.0 to 6.0 microns, with rounded ends. Spores ovoid and subtermi- nal, slightly swelling the cells. Motile. Gram-positive. Gelatin: No liquefaction. Agar deep colonies : Blackening of medium around colonies. Black increased by adding 0.1 per cent ferric chloride to medium. Milk: Action not recorded. Indole not produced. Hydrogen sulfide produced from cystine. Glucose and other carbohydrates not fer- mented. Nitrites not produced from nitrates. Coagulated albumin: No liquefaction. Blood serum: No liquefaction. Brain medium: Blackening but no diges- tion. Anaerobic. Temperature relations: Optimum, 55° C. Thermophilic, growing between 65° and 70° C. Not pathogenic for man, guinea pig, mouse, rat or rabbit. Distinctive character: Black colonies in
