THE CLASSIFICATION OF BACTERIA 375. 



long chains and filaments, with characteristic false branching ; rods of 

 variable length ; many clavate and spiral forms. 



Gelatin colonies. In 2 days, minute, white, 0.5 mm. ; microscopically, dense in- 

 centre, brown, with a similar staining of the surrounding gelatin. In 5 

 days the colonies may be 3 mm. ; the brownish discoloration extends far 

 into the gelatin. Each colony lies in a crateriform depression, with a 

 thick brown skin on the surface of the liquefied gelatin ; microscopically,, 

 with dense brownish centres and filamentous borders. 



Agar slant. A whitish line ; agar stained brown ; growth becomes wrinkled, 

 gristly, and adherent. 



Gelatin stab. In depth a slight growth, and later outgrowths ; on the surface,- 

 a button, which rapidly sinks ; gelatin a clear brown ; in 7 days a crateri- 

 form liquefaction, becoming stratiform. 



Potato. Growth thick, rough, grayish, wrinkled ; medium stained a deep brown. 



Bouillon. Growth at the bottom as dirty white flocculi ; the medium becomes 

 the color of brandy. 



Litmus milk. Becomes a deeper blue, and in 6 weeks cherry-red ; apparently 

 peptonized. 



Glucose gelatin stab. No gas or growth in depth. Indol produced. Grow at 



36°. 

 Habitat. Water and soil. 

 The Bismarck brown Cladothrix Houston (I.e.) is probably a variety of the 



above. 

 Habitat. Soil. 



5. Cladothrix profundus Ravenel 



I.e., 17. 



Long chains and filaments with false branching. 



Gelatin colonies. Deep: in 2 days, radiate, filamentous. Surface: in 2 days,, 

 minute round whitish dots in saucers of liquefied gelatin, brownish ; 

 microscopically with brownish centres and radiately filamentous borders,, 

 becoming concentric. A whitish, radially folded membrane on the sur- 

 face of the liquefied gelatin ; the medium is stained brownish. 



Agar slant. A tenacious leathery membrane, finely wrinkled, with a thinner 

 undulate edge ; bluish gray, with a metallic lustre ; growth adherent. 



Gelatin stab. In depth, a slightly arborescent growth ; on the surface lique- 

 faction crateriform, with vertical sides, becoming stratiform ; liquefaction 

 slow; liquefied gelatin a clear brown. 



Potato. A finely wrinkled colorless stripe, becoming grayish, spreading,, 

 rough, rugose, becoming thin, dry, brownish, and less rugose ; medium- 

 stained brownish. 



