NON-PATHOGENIC BACTERIA. 227 



ing; motile, with flagella at the ends; probably anaerobic; 

 forms spores located at the ends. 



Spirillum volutans. — Found in swamp water; very long 

 spirals with several turns; 1.5 to 2 // broad and 25 to 30 // 

 long; motile, with a flagellum at each extremity. The pro- 

 toplasm is granular. 



Spirillum undula. — ^Found in putrefying infusions con- 

 taining organic matter; a rather short spiral form with three 



't 



% 



«j^^, 



1 ^ 



'^ "^ 1 ? ^ 



ria^ 





Fig. 55. — Spirilla from Swamp Water. (X about 500.) 



turns or less, about i fjt thick and 8 to 12 // long; actively 

 motile, with a tuft of flagella at each extremity; has been 

 cultivated on agar. 



Spirilliun or Spirochseta plicatile, — Found in swamp 

 water; spiral forms of various lengths; sometimes 100 to 

 200 /i long; actively motile. 



The spirilla (vibrios or comma-shaped forms) closely re- 

 sembling the spirillum of cholera, wiU be considered in con- 

 nection with that organism. A form of chronic pseudomem- 



