THE CLASSIFICATION OF BACTERIA 273 



Gelatin stab. Liquefaction infundibuliform saccate, with a white-gray pellicle. 



Agar slant. Growth yellow-brown, moist, glistening, crumpled. 



Bouillon. Turbid, with a pellicle. 



Potato. Growth gray-yellow, moist, glistening, raised, becoming crumpled. 



H 2 S produced. Indol production feeble. 

 Milk. Coagulated, slightly alkaline. 

 Habitat. Widely distributed. 



Varieties. B. mesentericus-fuscus-granulatus Dyar. 



Agar cultures coarsely granulated ; reduce nitrates vigorously. 

 B mesentericus-fuscus-conststens Dyar. 



Gelatin colonies approaching in character to those of B. vulgaris. 



180. B. lactis No. 4 Fliigge 



Zeitsch. f. Hygiene, XVII, 1894, 294. 



From descriptions, not differentiated from the preceding. 

 Habitat. Milk. 



181. B. tenuis Trev. 



Tyrothrix tenuis Duclaux : Le Lait, Paris, 1887. 

 B. tenuis Trevisan : Genera, 1889. 



Morphology . Bacilli 0.6 : 3 o \l filaments. 



Gelatin colonies. Growth on agar, in milk, and in bouillon like B. subtilis. 



Potato. Growth like B. vulgatus. 



Habitat. Milk and cheese. 



182. B. tumescens Zopf 



Spaltpilze, 1885, 82. A. Koch : Bot. Zeitung, 1888, 313. 



Morphology. Bacilli short, about 1.7 /x broad; or filaments, which are bent 



and twisted. 

 Potato. Growth white, viscid, somewhat crumpled. 

 Habitat. Found in beets. 



183. B. gummosus Happ 



Philos. Diss., Basel, 1893. 



Morphology. Bacilli large, feebly motile. 



Potato and agar slant. Growth white, crumpled. Ferments cane sugar; 



medium viscous, with production of lactic and butyric acids and CO,. 

 Habitat. Associated with a slimy fermentation of digitalis infusions, etc. 



