Spheres, occurring in moderately long chains. Some cultures show very long chains in broth. Serology: No group-specific antigen has been demonstrated. Action on blood: Usually weak greening. No soluble hemolysin produced. Temperature relations : Growth at 45° but not at 50° C. No growth at 10° C. Occa- sional strains survive 60° C. for 30 minutes. Tolerance tests: Growth in broth con- taining 2 per cent NaCl but not in 6.5 per cent NaCl. No growth at pH 9.6 or in milk containing 0.1 per cent methjdene blue. Growth on 40 per cent bile blood agar. Litmus milk: No visible change. Final pH in glucose broth, between 4.0 and 4.5. No polysaccharide synthesized from sucrose. Acid from glucose, fructose, galactose, maltose and usually from sucrose and salicin. Raffinose and inulin are seldom fer- mented. No acid from arabinose, xylose, lactose, mannitol or glycerol. Starch is hydrolyzed on a favorable me- dium. Sodium hippurate and gelatin not hydrolj-zed. Esculin split. Ammonia not produced from arginine. Distinctive character: This species is ordinarily differentiated from the other viridans streptococci by its inability to fer- ment lactose. However, occasional strains in other species of this group also fail to ferment this sugar, thus necessitating the determination of the tolerance to bile, of the ability to hydrolyze starch and of other tests for final identification. Source and habitat: Predominating strep- tococcus in the alimentarj- tract of the horse. 14. Streptococcus therniophilus Orla- Jensen, 1916. (Maelkeri-Bacteriologi, 1916, 37; The Lactic Acid Bacteria, 1919, 136.) ther.mo'phil.us. Gr. noun therme heat; Gr. adj. philus dear, loving; M.L. adj. therniophilus heat-loving. Spherical or ovoid cells, 0.7 to 0.9 micron in diameter, occurring in pairs to long chains. Gram-positive. Serology: No group-specific antigen has been demonstrated. Action on blood: Most strains produce a weak greening reaction. Temperature relations: Optimum, be- tween 40° and 45° C. Grows at 50° but not at 53° C. No growth below 20° C. Survives 65° C. for 30 minutes. Tolerance tests: Very sensitive to salt as indicated by no growth in broth containing 2 per cent NaCl. No growth in milk con- taining 0.01 per cent methylene blue nor on 10 per cent bile blood agar. Litmus milk: Acid, curdled, followed by reduction of the litmus. No digestion. Final pH in glucose broth, between 4.0 and 4.5. Members of this species preferen- tially ferment the disaccharides sucrose and lactose and, therefore, may show a lower final pH from fermenting these sugars than from fermenting glucose. No polysaccharide is synthesized from sucrose. Acid from glucose, fructose, lactose and sucrose; seldom ferments the pentoses or raffinose. No acid from trehalose, maltose, inulin, glycerol, mannitol, sorbitol or sali- cin. Starch may be hydrolyzed on a favorable medium. Sodium hippurate and gelatin not hjfdrolyzed. Esculin not split. Ammonia not produced from arginine. Distinctive characters: This species may be easily recognized by its high tempera- ture range for growth, its thermal tolerance, its extreme sensitivity to salt and its in- ability to ferment maltose. Source: Milk and milk products. Em- ployed as a starter for Swiss cheese. Habitat: Unknown. 15. Streptococcus uberis Diernhofer, 1932. (Diernhofer, Milchw. Forsch., IS, 1932, 368; "Group III" non-hemolytic streptococci, Edwards, Jour. Comp. Path. Therap., 45, 1932, 43.) u'ber.is. L. noun uber udder, teat; L. gen. noun uberis of an udder. Description taken from Seeley (Jour. Bact., 6S, 1951, 107). Spheres, occurring in pairs or chains of moderate length. Serolog}-: A group-specific and distinctive antigen has been reported to exist among the strains tested (Seeley, loc. cit.), but the sta-
