THE CLASSIFICATION OF BACTERIA 31 1 



8. Ps. Fairmontensis (Wright) 



B. Fairmontensis Wright: I.e., 458. 



Morphology. Bacilli of medium size, ends rounded, in pairs and filaments. 



Gelatin colonies. Deep-, round oval, dense, granular, dark grayish brown : in 

 3 days, surrounded by a zone of liquefied gelatin. Surface: in 2 days, 

 round, white, translucent disks, 1-2 mm. ; microscopically, with dark 

 centres with a greenish shimmer and thinner edges, and faint radial lines. 



Gelatin stab. Liquefaction crateriform, extending to the walls in 2-3 days ; 

 little growth along needle track. 



Agar slant. Growth grayish white, glistening. 



Potato. Growth granular, elevated, spreading, the color of the medium, 

 becoming brownish, viscid. 



Litmus milk. Decolorized. No growth at 36 . Jndol produced. 



Habitat. Water. 



9. Ps. liquida (Frankland) 



B. liquidus Frankland : Zeitsch. f. Hygiene, VI, 1889, 382. 



B. liquefaciens-communis Sternberg: Manual, 1892. 



B. aquatilis-communis Kruse : Flugge, Die Mikroorganismen, 1896, 315. 



Morphology. Bacilli 0.6: 1.2-5 fi. Flagella polar. 



Gelatin colonies. Round, crateriform, turbid ; edge finely granular, not ciliate. 



Agar slant. Growth translucent, gray. 



Gelatin stab. In 2 days, a large, saccate liquefaction, turbid, becoming clear. 



Potato. Growth yellowish brown, pinkish flesh-colored. Nitrates reduced. 



Habitat. Water. 



10. Ps. nebulosa (Wright) 



B. nebulosus Wright : I.e. 



Morphology. Bacilli of medium size ; flagella polar. 



Gelatin colonies. Deep-, round, dark, granular. Surface: round, thin, gray, 

 translucent, hazy ; centre white, surrounded by a whitish ring ; micro- 

 scopically, centre dark brownish, granular, surrounded by a thin, trans- 

 parent zone. 



Gelatin slant. Growth viscid, whitish; lines a shallow furrow, with short, 

 lateral outgrowths. 



Agar slant. Growth a thin, translucent stripe. 



Bouillon. Turbid, with a sediment. 



Potato. A scanty growth, if any. 



