THE CLASSIFICATION OF BACTERIA 227 



CLASS II. WITHOUT ENDOSPORES. AEROBIC AND FACULTATIVE 

 ANAEROBIC. COLONIES ON GELATIN PLATES NOT AMEBOID 

 OR PROTEUS-LIKE. GELATIN NOT LIQUEFIED. STAINED BY 

 GRAM'S METHOD. 



I. Colonies on gelatin plates flat, spreading, B. coli-like 



A. Gelatin surface distinctly coli-like ; rather thick, and yellowish brown 



by transmitted light, or granular. 



1 . Gas generated in glucose bouillon. 



63. B. muripestifer Kruse. 



64. B. aerogettes (Schow). 



2. No gas generated in glucose bouillon. 



65. B. Shiga. 



3. Action on glucose bouillon not stated. 



66. B. color abilis Kruse. 



B. Gelatin surface colonies thin, translucent. 



67. B. exanthematicus Kruse. 



68. B. accidentalis Kruse. 



II. Colonies on gelatin of the aerogenes type. 



69. B. endocarditis Weichselbaum. 



63. B. muripestifer Kruse. 



B. der M&useseuche Laser: Centralblatt f. Bakteriologie, XI, 1892, 184. 

 B. muripestifer Kruse: Fliigge, Die Mikroorganismen, 1896, 432. 



Morphology. Bacilli short rods, with polar stain. Flagella peritrichic 



Gelatin colonies. Deep-, round, brownish. Surface: spreading, coli-like. 



Gelatin stab. Surface growth flat. 



Bouillon. Turbid, with a slight membrane. 



Potato. Growth brownish. 



Litmus milk. Acid. 



Pathogenesis. Subcutaneous inoculations of mice and field mice cause death 

 in 2 days, and by feeding in 3-10 days; bacilli in all the organs. Patho- 

 genic to rabbits, guinea pigs, and pigeons. Very similar to B. murium, 

 but distinguished by the Gram reaction. 



Habitat. Associated with a plague of field mice. 



64. B. aerogenes Schow 



Coccobacillm aerogenes^vesicce Schow: Centralblatt f. Bakteriologie, XII, 1892, 740. 



Morphology. Bacilli short coccoid ; no threads. 



Gelatin colonies. The deep colonies are small, round, and yellowish ; surface 

 colonies, flat, yellowish white, glistening ; borders irregular to erose, be- 

 coming the size of millet seed and yellowish. 



