I62 BACTERIOLOGY 



JJtmus milk. Alkaline; not coagulated, /k^ij/ negative. 

 Glucose bouillon. No gas. No growth at 36°. 

 Habitat. Water. 



107. Bact. radiatum Chester I.e. 



Morphology. On agar short ovals — longerforms; 0.7: 1.0-3. o/j.; occur singly, 

 with little tendency to form filaments or chains. Decolorized by Gram's 

 method. Flagella absent. Aerobic, grow only in open end of fermenta- 

 tion tube. No growth at 37° C. 



Gelatin colonies. Deep: round, entire, amorphous, homogeneous, yellow- 

 brown. Surface colonies: in 2-3 days, thin, flat, slightly depressed, i 

 mm. ; in 4-5 days, colonies 3-5 mm., depressed, due to liquefaction, with 

 a large central dirty white nucleus, irregular or ameboid in form, with 

 irregular radial extensions. Microscopically, in 2 days, an indistinctly 

 defined yellowish brown nucleus, becoming lighter and colorless ex- 

 teriorly ; refraction low ; edge faintly defined, erose, embayed, lobed. 

 Coli — proteus-like. 



Gelatin stab. In depth, a scanty filiform growth ; on the surface, a crateriform 

 liquefaction, becoming stratiform. 



Agar slant. A pure white, dense, opaque streak. 



Bouillon (neutral). A slight, uniform turbidity, which persists for 5 weeks. 

 No pellicle, and only slight sediment. 



Potato. A thick, raised, slimy whitish streak, becoming yellowish — brownish. 



Milk. Coagulated after 2-5 weeks ; medium may become slightly brownish, 

 and has a foetid odor. 



Litmus milk. For the first 10 days, a slightly darker blue, becoming, in 10 

 days, slightly acid. Early cultures reduced litmus. Indol negative. No 

 gas in glucose bouillon, and slight acid production. No reduction of 

 nitrates to nitrites. No growth in 1.5 per cent normal HCl bouillon. 

 Cultures show only a slight fcetid odor. 



^Habitat. Soil. 



■CLASS V. WITHOUT ENDOSPORES. AEROBIC AND FACULTATIVE 

 ANAEROBIC. PRODUCE PIGMENT ON GELATIN OR AGAR. PIG- 

 MENT YELLOWISH, GELATIN LIQUEFIED. 



I. Growth on potato. 



A. Growth on potato yellowish. 



I. Gelatin colonies radiate filamentous, branched — arborescent. 

 108. Bcut. arborescens (Frankland). 



