MICROCOCCUS LANCEOLATUS. 511 
medium for these parasites in the body, brought about 
by an abnormal condition of the mucous membranes 
from exposure to cold, or a reduction of the vital re- 
sisting power of the tissue cells in any of the internal 
organs, caused by disease, traumatism, excesses of vari- 
ous kinds, ete. , to readily comprehend how an individual 
may become infected with pneumonia, either primarily 
affecting the lungs and secondarily other organs in the 
body, or primarily attacking the middle ear, the pericar- 
dial sac, the pleura, the serous cavities of the brain, etc. 
From statistics collected by Netter the following per- 
centages of diseases were caused by the ‘‘ diplococcus 
pneumonie’’ ; 
Pneumonia : ‘ . 65.9 per cent. in adults. 
Bronchopneumonia . . 168 ne 
Meningitis . , i . 13.0 ee 
Empyema . ; : - 85 fe 
Otitismedia .- . 2 Ae oH af 
Endocarditis. ; = ghz tS 
In 46 consecutive pneumococcus infections in chil- 
dren there were : 
Otitis media : i A : ‘ 29 cases. 
Bronchopneumonia_ . ‘ , ; TZ 
Meningitis . ‘ . ‘ ' ‘ 2 
Pneumonia . ; ‘ i F 1 “ 
Pleurisy . 3 : ‘ : : i 
Pericarditis 1 * 
Varieties of the Micrococcus Lanceolatus. The ubi- 
quity of this organism and the irregularity of its 
behavior under varying conditions have opened a wide 
field of discussion among bacteriologists. As com- 
monly found, for instance, in the saliva of different 
healthy individuals, and even in that of the same in- 
dividual at different times, it often varies in virulence; 
