CHAPTER XXVIII. 



MICROCOCCUS LANCEOLATUS (PNEUMOCOCCUS ; MICRO- 

 COCCUS PNEUMONIA CROUPOS2E OF STERNBERG; 

 MICROCOCCUS OF SPUTUM SEPTIC^MIA AND DIPLO- 

 COCCUS OF FRAENKEL; DIPLOCOCCUS PNEUMONIA 

 OF WEICHSELBAUM). 



THIS micrococcus was first observed by Sternberg, in 

 1880, in the blood of rabbits inoculated with his own 

 saliva (and almost simultaneously by Pasteur under 

 similar conditions), whence it was called by Sternberg 

 micrococcus Pasteuri. It was subsequently described 

 by Talamon (1883), and demonstrated by him to be 

 capable of producing fibrinous pneumonia in rabbits 

 when introduced into the parenchyma of the lung of 

 these animals. In 1885 and 1886 this micro-organism 

 was subjected to an extended series of investigations 

 by A. Fraenkel, Sternberg, Weichselbaum, Netter 

 and others, and proved by them to be the chief etio- 

 logical factor in the production of lobar or croupous 

 pneumonia in man. 



Morphology. Very irregular; occurs as spherical or 

 oval cocci, usually united in pairs, but sometimes in 

 longer or shorter chains consisting of from three to six 

 or more elements and resembling the streptococcus. The 

 individual cells, as they commonly occur in pairs, are 

 somewhat oval in shape, being usually pointed at one 

 end hence the name lanceolatus, or lancet-shaped. 



