340 BACTERIOLOGY 



Gelatin colonies. In 24 hours, small white points; microscopically, round, 

 entire, dark greenish brown, becoming dark yellow in centre with lighter 

 borders, becoming liquefied. Colonies generally retain their sharp contour. 



Gelatin stab. Grow like cholera, but the gelatin liquefied more rapidly. 



Agar slant. Growth yellowish white. 



Potato. No growth either at 20 or 37. In bouillon or pepton solution, no 

 indol reaction. 



Pathogenesis. Very feebly pathogenic (Koch), or not at all so. 



Habitat. Isolated from cheese. 



14. Microspira choleroides (Bujwid) 



Vibrio choleroides Bujwid: Centralblatt f. Bakteriol, XIII, 1893, 120. 

 Morphology. Bacilli like Msp. comma, but movements not so rapid. 

 Gelatin colonies. At low temperatures, cholera-like colonies ; at higher 



temperatures colonies larger, and do not sink deeply into the gelatin; 



microscopically the contour is more regular than cholera, and only finely 



granular. 

 Gelatin stab. Growth only on the surface, with slight liquefaction, or an air 



bubble may be produced. 



Agar slant. A good growth, with an odor of methyl-mercaptan. 

 Bouillon. Slightly turbid ; no pellicle. 

 Habitat. Water. 



15. Microspira Weibeli 



Vibrio saprophiles $ Weibel : Centralblatt f. Bakteriol., II, 1887, 469. 



Morphology. Bacilli slender curved rods of about the thickness of tubercle 

 bacilli and about 2.0 /x, long ; ends blunt, commas S forms ; long fila- 

 ments do not occur. Grow slowly at room temperatures. 



Gelatin colonies. Do not exceed 0.3 mm. ; microscopically, round, yellowish 

 brown. 



Gelatin stab. A slight growth in depth ; on the surface, growth thin, white, 

 spreading. 



Agar slant. Growth creamy, yellowish white, viscid. 



Potato. Growth thin, glistening, varnish-like, of a dirty brownish gray color. 



Habitat. Isolated from putrefying hay infusion. 



1 6. Microspira denitrificans (Sewerin) 



B. denitrificans Sewerin: Centralblatt f. Bakteriol., 2te Abt., I, 1895, 162, and IV, 451. 

 MorpJiology. Bacilli on agar 0.5 : 2-4 /x ; on nitrate bouillon, comma forms 

 longer vibrios and Spirillum forms. Older cultures show branched indi- 

 viduals and other involution forms. 



