108 THE PATHOGENIC MICROCOCCI. 



CHAPTER IX. 



THE OTHER PATHOGENIC MICROCOCCI AND ALLIED 

 BACILLI MICROCOCCUS PNEUMONIA, EPIDEMIC 

 CEREBROSPINAL MENINGITIS, AND MALTA FEVER. 



PNEUMONIA. 



I. Micrococcus Pneumonias Crouposae (Diplococcus 

 Pneumonias ; Micrococcus Pasteuri ; Micrococcus 

 of Sputum Septicaemia). 



History. The Micrococcus pneumonice crouposce was discov- 

 ered in September, 1880, by Steinberg, in the blood of rabbits 

 which he had inoculated subcutaneously with his own saliva ; 

 also by Pasteur, in December, 1880, in the saliva of a child 

 who had died of pneumonia in a Paris hospital. This was 

 confirmed and studied by Fraenkel, Weichselbaum, and others. 



It is found: a. in the saliva of about 50 per cent, of healthy 

 individuals, b. in the rusty sputum of pneumonic patients 

 and in the fibrinous exudation of 75 per cent, of the cases of 

 pneumonia, c. in a large number of cases of meningitis com- 

 plicating pneumonia or associated with pneumonia, d. occa- 

 sionally where no pneumonia exists, e. also in abscesses. 



Morphology. Micrococcus pneumonice is a small oval coccus 

 appearing alone or united in pairs, occasionally forming chains 

 with four or five elements resembling streptococci. In the 

 animal body it is generally oval and double, as a diplococcus, 

 surrounded by a capsule (Fig. 50). 



In solid media it grows as a micrococcus, a diplococcus, or 

 as a chain like the streptococcus with scarcely more than four 

 or five elements. In liquid media the cells are more nearly 

 round, and the chains contain sometimes as many as eight or 

 ten elements (Fig. 51). 



It stains by the anilin dyes, and also by Gram's method. 



Biologic Characters. The Micrococcus pneumonice is aerobic 

 and facultative anaerobic. Like most cocci it is non-motile, 



