196 BACTERIOLOGY. 



individuals, having been found by Sternberg in the oral 

 cavity of about 20 per cent, of healthy persons exam- 

 ined by him. It is constantly to be detected in the 

 rusty sputum of patients suffering from acute fibrinous 

 pneumonia. Its presence has been detected in the 

 middle ear, in the pericardial sac, in the pleura, in the 

 serous cavities of the brain, and indeed it may probably 

 penetrate from its primary seat in the mouth to almost 

 any of the more distant organs. 



The organism is commonly found as a diplococcus, 

 though here and there short chains of four to six indi- 

 viduals joined together may be detected. The mor- 

 phology of the individual cells is more or less oval, or 

 more strictly speaking, lancet-shaped, for at one end 

 there is commonly a pointed appearance. When joined 

 in pairs the junction is always between the broad ends 

 of the ovals, never between the pointed extremities. 



In preparations directly from the sputum or from the 

 blood of animals, a delicate capsule may frequently be 

 seen surrounding them. This occurs only in prepara- 

 tions directly from the body and is not seen in pre- 

 parations from cultures. 



This organism grows under artificial conditions very 

 slowly, and frequently not at all. 



When successfully grown upon the different media it 

 presents somewhat the following appearance : 



On gelatin it grows very slowly, probably owing in 

 part to the low temperature at which gelatin cultures 

 must be kept. If development occurs it appears as 

 very small whitish or blue-white points on the plates. 

 These very small colonies are round, finely granular, 

 sharply circumscribed, and slightly elevated above the 



