XL] 



BACILLUS : PATHOGENIC FORMS. 



115 



and Greenfield l maintain, that continued transference weakens 

 the action of the bacilli ; as long as the cultures remain pure, 

 not contaminated and finally suppressed by accidental in- 

 nocuous bacilli, the anthrax-bacilli retain their full virulence. 



FIG. 81. NETWORK OF CAPILLARIES FILLED WITH BACFLLUS AMTHRACIS ; FROII 

 THE OMESTVM OK A RABBIT DEAD OF ANTHRAX. 



1. Extravasation of the bacilli. 



2. Capillaries filled with the bacilli. 



Magnifying power 350. 



Cultures of the blood-bacilli at 20 to 38 C. in fluid media, 

 e.g. neutral pork-broth, during the first or second week, 

 are virulent to mice, guinea-pigs, and rabbits ; but after 

 that they lose their power on mice, provided the growth 

 takes place only in the depth, and no spores are formed ; but 

 they retain it, as regards guinea-pigs and rabbits, as long as 



1 Proceedings of the Royal Society, June 17, 1880. 



