CHAPTER XXVIII. 
MICROCOCCUS LANCEOLATUS (PNEUMOCOCCUS ; MICRO- 
COCCUS PNEUMONLE CROUPOSH OF STERNBERG ; 
MICROCOCCUS OF SPUTUM SEPTICHMIA AND DIPLO- 
COCCUS OF FRAENKEL; DIPLOCOCCUS PNEUMONIE 
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; occuyg 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. 
