THE CLASSIFICATION OF BACTERIA 21 3 



Pathogenesis. Subcutaneous inoculation of house mice and field mice cause 

 death in 3 days. Bacilli in the organs ; spleen enlarged. The latter 

 also infected by feeding. 



Habitat. Found by Lbffler as the cause of an epidemic in mice. 



19. B. intestinalis Dyas- Keith 



Mass. Inst, of Technology Quarterly, VI, 3 ; ref. Centralblatt f. Bakteriol., 

 XVI, 1894, 838. 



Morphology. Bacilli 1.0:1.2/^.; somewhat thicker than B. coli. Grow at 



37°. Cultural characters like B. coli. 

 Pathogenesis. Doubtful. 

 Habitat. Isolated from the excrement of the horse. 



20. B. meningitidis Neumann-Schaeffer 



Virchow's Archiv, CIX, 1887, 477. 



Morphological and cultural characters like B. typhosus. 



Potato. Growth gray white, viscid. No gas in lactose bouillon. 



Pathogenesis. Subcutaneous inoculation of guinea pigs causes a pyogenic 



reaction. 

 Habitat. Isolated from a case of purulent meningitis. 



21. B. typhosus Zopf 



■ B. der Abdominaltyphus Eberth : Virchow's Archiv, LXXXI, 1880. 

 B.fyphosus Zo^i: Spaltpiize, 1885, 124. 



Morphology. Bacilli 0.5-0.8: 1-3 /a — filaments. Flagella peritrichic, 8-14, 



long, undulate. 

 ■Gelatin colonies. Deep : round, gray to yellowish brown, entire. Surface : 



at first small,' punctiform, becoming flat, roundish, gray, glistening, with 



irregular borders ; microscopically, colorless, translucent, becoming 



grayish yellow, darker in the centre, marmorated ; border undulate to 



lobate ; strongly refracting. 

 ■Gelatin stab. Growth in depth filiform — beaded — tuberculate ; on the 



surface, growth thin, whitish, irregular. 

 Bouillon. Slightly turbid, less so than B. coli. 

 Milk. Not coagulated, only slightly acid. 

 Potato. Growth a pure white glistening streak, not very thick, or scarcely 



visible. 



