PATHOGENIC BACTERIA. 



119 



principle is ascribed to an anti-toxin formed in the tissues by 

 the diluted proteids, and this anti-toxin neutralizes the toxicity 

 of the strong virus. 



Bacillus of Rhinoscleroma. (Frisch. 1882.) It was found in 

 the tissue of a rhinoscleroma, but resembles the Friedlander 

 bacillus in nearly every respect, and as the disease rhinoscleroma 

 was not reproduced by the inoculation of the bacillus in animals, 

 it can be considered identical. The growth, cultures, and pro-, 

 perties are the same as the pneumobacillus of Friedlander. 



Micrococcus Tetragenus. (Koch. Gaffky). 



Origin. Koch found this microbe in the cavity of a tubercu- 



lous lung. Gaflfky, in 1883, studied its patho- 

 genic actions and gave it the name it now 

 bears. 



Form. Cocci which are gathered in the tis- 

 sues in groups of four, forming a square, a 

 tetrad. See Fig. 65. In artificial culture, 

 sometimes found in pairs. A capsule of light 

 gelatinous consistence surrounds each tetrad. 



Properties. They are immobile; do not 

 liquefy gelatine. 



Growth. They grow well on all nutrient 

 media at ordinary and brood temperatures ; 

 are facultative aerobic. They grow slowly. 



Colonies in gelatine plates. In two days, 

 little white spots, which when on the surface 

 form little elevations of a porcelain-like ap- 

 pearance ; under low power they are seen very 

 finely granulated. 



Stab Culture. Small round separated colo- 

 nies along the needle-track, and on the sur- 

 face a button-like elevation, a form of " nail 

 culture." See Fig. 66. 



Potato. A thick slimy layer which can be 

 loosened in long shreds. 



Staining. Colored with the ordinary aniline 

 stains. Gram's method also applicable. 



Pathogenesis. White mice and guinea-pigs 

 die in a few days of septicaemia when injected 



Fia. 66. 



.1 I 



Stab Culture. 



Micrococcus tetra- 



genus. 



