BACTERIUM PNEUMONIA. 333 



indeed it may penetrate from its usual site of develop- 

 ment in the mouth to 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 may be detected. (Fig. 63.) The individual 

 cells are more or less oval, or, more strictly speaking, 

 lancet-shaped, for at one end they are commonly pointed. 

 When joined in pairs the junction is always at the 

 broad ends of the ovals, never at the pointed extremities. 

 When in chains only the terminal cells are pointed, and 

 then at their distal extremities. 



As already stated, in preparations directly from the 

 sputum or from the blood of animals a delicate capsule 

 may frequently be seen surrounding them. Though 

 fairly constant in preparations directly from the blood 

 of animals and from the sputum or lungs of pneumonic 

 patients, the capsule is but rarely observed in artificial 

 cultures. Occasionally in cultures on blood-serum, in 

 milk, and on agar-agar it can, according to some 

 authors, be detected ; but this is by no means constant, 

 or even frequent. 



Even under the most favorable artificial conditions 

 this organism grows but slowly and frequently not at 

 all. 



When successfully grown upon the different media it 

 presents somewhat the following appearances : 



On gelatin its development is very limited and often 

 no growth at all occurs. This is probably due in part 

 to the low temperature at which gelatin cultures must 

 be kept. If development occurs, the growth appears 

 as minute whitish or blue-white points on the plates. 

 These very small colonies are round, finely granular, 

 sharply circumscribed, and slightly elevated above the 



