THE CLASSIFICATION OF BACTERIA 225 



Gelatin stab. Growth filiform in depth ; surface growth white, scarcely 



visible, covers the entire surface. 

 Gelatin slant. A limited yellowish white stripe, with a thin colorless border, 



and with outgrowths. 

 Agar colonies. In 1-2 days at 30, the deep colonies are small, white, and 



entire; the surface colonies thin, soft, colorless, limited, with erose 



borders. 



Nitrate bouillon. A membrane on the surface ; reduction to nitrites. 

 Habitat. Straw, earth, and horse manure. 



59. B. Stutzeri (Lehmann- Neumann) 



B. denitrificans, II, Burri-Stutzer : Centralblatt f. Bakteriol., IV, 1898. 

 Bact. Stutzeri I^ehmann-Neumann, Bak. Diag., 1896, 2te Abt., 1898, 408. 



Morphology. Bacilli ; on agar rods with rounded ends, often spindle-shaped, 



0.5-1.0: i. 5-2. 5-4 /A; in bouillon, only 0.25-0.3 /x, thick. Polar stain. 

 Gelatin colonies. In 4 days the deep colonies are small, white, entire; the 



surface colonies thin, whitish, translucent, with somewhat ragged edges. 

 Agar colonies. In 2 days at 30 the deep colonies are small, yellowish white, 



entire; the surface colonies thin, 5-10 mm. 



Agar slant. Growth soft, flat, dry, grayish, becoming rather moist, glistening. 

 Gelatin slant. Growth thin, milky-white, with fine radial striping and 



undulations. 

 Gelatin stab. In depth growth pearly ; on the surface growth milky-white, 



soft, dry, becoming somewhat slimy. 

 Nitrate bouillon. A weak turbidity; in 2 days a membrane. Nitrates 



reduced. 

 Habitat. Straw, earth, air. 



60. B. centropunctatus (Jensen) 



Bact. centropunctatum Jensen : Centralblatt f. Bakteriol., IV, 

 2te Abt., 1898, 410. 



Morphology. Bacilli ; on agar coccoid, 0.3-0.5 /x, with a capsule. In nitrate 



bouillon, morphology like B. Stutzeri. In anaerobic cultures bacilli large, 



ovoid, 0.5-1.0 /A. 

 Gelatin colonies. In 4 days the deep colonies are small, white, entire ; the 



surface colonies thick, moist, glistening, grayish, becoming whitish. 

 Agar slant. Growth thin, soft, becoming in 2 days thick, glistening, grayish,. 



slightly raised in the middle. 



Gelatin slant. Growth milky-white, slimy, glistening, with long outgrowths. 

 Q 



