soluble hemolysin produced is distinct from streptolysins O and S. Not fibrinolytic. Temperature relations: No growth at 10° or 45° C. Does not survive 60° C. for 30 minutes. Tolerance tests: Same as for Streptococcus pyogenes. Litmus milk: Acid, usually does not curdle. Does not reduce litmus before curdling. Final pH in glucose broth, between 4.6 and 5.0. Acid from glucose, lactose, sucrose, sor- bitol and salicin. May ferment maltose. No acid from the pentoses, trehalose, rafiinose, inulin, glycerol or mannitol. Starch usually hydrolyzed. Sodium hip- purate not hydrolyzed. Gelatin not lique- fied; esculin split. Ammonia produced from arginine. Distinctive characters: This species may be distinguished from closely allied species by its ability to ferment sorbitol but not trehalose and by its inability to lyse human fibrin. Source: Blood stream, inflammatory exu- dates and lesions of diseased animals. Not known from man. Habitat: Disease process of domestic and laboratory animals. (Horse: endometritis, fetus. Hog: Septicemia. Cow: septicemia, metritis, fetus. Fowls: slipped tendon. Guinea pig: lymphadenitis. Rabbit: sep- ticemia. Fox: pneumonia.) 4. Streptococcus equi Sand and Jensen, 1888. {Bacillus adenitis equi Baruchello, Soc. veter. de Venetie, Undine, 1886; also see Baruchello, Giornale di anatomia, fisiologica et patologia degli animali domes- tici, Pisa, Sept., 1887; Sand and Jensen, Deutsche Ztschr. f. Tiermed., IS, 1888, 436, dated December 27, 1887, Veterinary Con- gress, Copenhagen, 1887.) e'qui. L. noun equus horse; L. gen. noun. equi of a horse. Ovoid or spherical cells 0.6 to 1 micron in diameter; sometimes in pus the long axes of the cells are transverse to the long axis of the chain and at other times parallel with the long axis of the chain, in the latter case resembling streptobacilli; bacillary forms are not rare; occur in pairs, short or long chains; very long chains common in broth cultures. Capsules often pronounced in blood of infected mice and when grown in serum. Gram-positive. Generally poor growth in broth culture; growth increased by serum. Serology: Belongs to Lancefield's group C. Cultures are generally poor antigens for production of agglutinating serum. Action on blood: Beta hemolytic. The blood agar colonies are small and watery and dry out rapidly leaving flat, glistening colonies. Growth in serum broth yields a soluble hemolysin that is distinct from streptolysins O and S. Not fibrinolytic. Temperature relations: Optimum tem- perature, 37° C. Growth slow at 20° C. No growth at 10° or 45° C. Does not survive 60° C. for 30 minutes. Tolerance tests : Fails to grow in presence of 6.5 per cent NaCl or in skim milk con- taining 0.1 per cent methylene blue. No growth in media adjusted to pH 9.6 or on blood agar containing 40 per cent bile. Litmus milk: No change. Final pH in glucose broth, between 4.8 and 5.5. Acid from glucose, maltose, sucrose and salicin. No acid from arabinose, lactose, trehalose, rafiinose, inulin, glycerol, man- nitol or sorbitol. Sodium hippurate not hydrolyzed. Gela- tin not liquefied; esculin not split. Ammonia produced from arginine. High virulence for mice, but low or no virulence for rabbits and guinea pigs. Distinctive characters: This species is distinctive by its inability to ferment tre- halose, sorbitol, glycerol or lactose. Source: Pus from lesions and mucous membrane of upper respiratory tract of horses. Habitat: Found only in strangles in horses. 5. Streptococcus dysgalactiae Diern- hofer, 1932. (Diernhofer, Milchw. Forsch., 13, 1932, 368; Group II, Minett, Proc. 12th Internat. Vet. Cong., 2, 1934, 511; Strep- tococcus pseudoagalactiae Plastridge and
