118 ESSENTIALS OF BACTERIOLOGY. 



very readily. The capsule stained the same way as that of the 

 Friedlander bacillus. 



Pathogencsis. Rabbits and guinea-pigs, if subcutaneously in- 

 jected, die in the course of a couple of days with septicaemia. 

 (0.1 c.cm. of a fresh bouillon culture suffices.) 



Autopsy shows greatly enlarged spleen and myriads of bacilli 

 in the blood and viscera, the lungs not especially affected. If 

 injected per trachea, a pneumonia occurs. In man in 90 per 

 cent, of croupous pneumonia they are found and usually only 

 during the existence of the " prune juice" sputum, i. e., the first 



stage. 



FIG. 65. 



Micrococcus tetragenus in^sputum (tubercle bacillus also). 



They have also been found in pleuritis, peritonitis, pericarditis, 

 meningitis, and endocarditis. They stand in some intimate re- 

 lation with all infectious inflammations of the body. Their 

 presence in healthy mouth secretion does not speak against it, it 

 requiring some slight injury to allow this ever-present germ to 

 develop the disease. 



Anti-toxin of Pneumonia. (Klemperer.) 



The injection of very diluted cultures of the virulent bacilli in- 

 travenously has produced an immunity in rabbits and guinea- 

 pigs. The serum of such artificially immune animals when filtered 

 through a Chamberland filter and injected into a rabbit suffer- 

 ing witli pneumonia, cured the same ; or when injected into a 

 susceptible animal produced in it immunity very quickly. This 



