THE CLASSIFICATION OF BACTERIA 307 



b. Produce pigment on gelatin or agar. Class III, p. 314. 



c. Colonies colorless, or colored only slightly yellowish-greenish, 



but with a yellow green or blue green fluorescence. Class IV, 

 p. 320. 

 2. With endospores. Class V, p. 326. 

 B. Do not grow in nutrient gelatin or other organic media. 



Class VI, Nitromonas Group, p. 329. 

 II. Cell plasma with a reddish tint, with also sulphur granules. Class VII, 

 P- 329- 



CLASS I. WITHOUT ENDOSPORES. AEROBIC AND FACULTATIVE 

 ANAEROBIC. NON-CHROMOGENIC. GELATIN NOT LIQUEFIED. 



I. Gas generated in glucose bouillon. 



A. Indol produced. 



1. Ps. sinuosa (Wright). ^ 



B. No indol produced. 



2. Ps. monadiformis (Kruse). 



II. No gas generated in glucose bouillon. 



A. Potato cultures whitish-grayish. 



3. Ps. ambigua (Wright). 



4. Ps. catarrhalis. 



B. Potato cultures brownish. 



5. Ps. nexibilis (Wright). 



1. Ps. sinuosa (Wright) 



B. sinuosus Wright: I.e., 440. 



Morphology. Bacilli medium-sized, ends rounded, pairs filaments. A polar 



flagellum ; some bacilli probably have 2-4 fiagella. 

 Gelatin colonies. In 3 days, 3 mm., thin, delicate, translucent, irregular, 



sinuous ; centres brownish, grained ; becoming 6 mm., with radial 



foldings. 

 Gelatin slant. Growth grayish white, glistening, translucent. 

 Agar slant. Growth scanty, limited. 

 Bouillon. Turbid, with a sediment ; no pellicle. 

 Potato. Growth gray-brown, moist, not thick, rather rough, spreading. 



Indol slight. Grow at 36 . 

 Milk. Not coagulated. 

 Habitat. Water. 



