THE CLASSIFICATION OF BACTERIA 341 



Gelatin colonies. Small, white, entire. 



Gelatin stab. In depth, growth pearly. 



Agar colonies. In 2 days, at 30°, 1-2 mm., bluish white, slimy. 



Agar slant. In 2 days, growth grayish white, limited, becoming spreading. 



Nitrate bouillon. Turbid, with a slight membrane ; nitrates reduced. 



Habitat. Isolated from horse manure. 



17. Microspira saprophile (Weibel) 



Vibrio safrophiles A. Weibel: Centralblatt f. Bakteriol., II, 1887, 469. 



Morphology. Bacilli bent rods 3.0 /u. long to S forms, rarely filaments. 



Gelatin colonies. Deep: round, entire, yellowish brown, concentric, edges 

 serrate. Surface : fiat, yellowish white ; microscopically, with dark yel- 

 lowish gray centres, paler at borders, finely granular. 



Gelatin stab. In depth, growth thin, veily ; on the surface, growth thin, 

 spreading, white. 



Agar slant. Growth dirty white, spreading ; agar colored below. 



Potato. Growth slimy, pasty, yellowish red, becoming chocolate-brown. 



Bouillon. Turbid, with a yellowish granular sediment. 



Habitat. Isolated from putrid hay infiision and sewer mud. 



18. Microspira cloaca 



Vibrio saprophiles Y Weibel : I.e. 



Bacilli like the preceding, but twice as large, rarely forms long-twisted threads ; 



a great tendency to produce involution forms. 

 Gelatin colonies. Deep : ovoid, entire, granular ; centres orange-colored, with 



light yellow outer zones. Surface: flat, dirty white — opalescent, with 



prominent white centres ; microscopically, like B. coli; borders irregular 



— lobed, marmorated — spotted. 

 Gelatin stab. In depth, growth filiform ; on the surface, a whitish expansion. 

 Agar slant. Growth spreading, dirty white. 

 Potato. Growth yellowish brown — brown, moist, glistening, becoming dry, 



tough and dark brown. 

 Bouillon. Turbid, with a thick firm pellicle. 

 Habitat. Isolated from sewer mud. 



19. Microspira terrigena (Giinther) 



Vibrio terrigenus Gunther : Centralblatt f. Bakteriol., XVI, 1894, 746. 

 Morphology. Bacilli show at each end one or several flagella. 

 ■Gelatin colonies. Entire, small, structureless. 



