226 MANUAL OP BACTERIOLOGY. 



production of gas and alcohol. It belongs in the same group 

 as B. coli communis and B. lactis aerogenes (see Part IV.). 



There are numerous other bacteria, such as the Bacterium 

 acidi lactici, which cause the formation of lactic acid in 

 milk. 



Bacterium ureae. — ^A short, thick bacillus with rounded 

 ends; not motile; aerobic; found in ammoniacal urine ; grows 

 slowly at room temperature upon gelatin, which is not Hque- 

 fied; decomposes urea; forms ammonium carbonate. 



Bacterium Zopfii. — Found in the intestines of hens, in 

 water and in fecal matter; a bacillus 0.75 to i /^ broad and 2 

 to 5 /i long; may form threads. Actively motile; does not 

 liquefy gelatin; aerobic; involution forms are often seen and 

 they have been described as spores; grows rapidly, best at 

 20° C. upon gelatin; forms branching zooglceae. It is a mem- 

 ber of the same group as B. proteus (see Part IV.). 



Spirillum rubrum. — Found by Esmarch in the putrefying 

 cadaver of a mouse; short spirals twice the breadth of the 

 cholera spirillum, usually with one to three turns; in bouillon 

 growing into long spirals; motile, with flagella; spore forma- 

 tion doubtful; facultative anaerobic; does not liquefy gelatin; 

 grows slowly, best at about 37° C. on the ordinary media; 

 produces a wine-red pigment only when the air is excluded. 



Spirillum or Spirochaeta dentium. — Found in the mouths 

 of healthy persons, on the margins of the gums when they 

 are covered with a dirty deposit; long spirals with several 

 windings, uneven in thiclmess; has not been cultivated. 



Spirillum sputigenum. — Found in the human mouth in 

 healthy persons at the margin of the gums; curved rods or 

 short spirals which resemble the spirillum of cholera in form; 

 has not been cultivated. 



Spirillum rugula (Vibrio rugula). — Found in swamp water, 

 in fecal matter and in the tartar of the teeth; a curved rod 

 0.5 to 2.5 fj- broad and 6 to 8 /i long, having one flat spiral wind- 



