SPUTUM SEPTICEMIA 387 



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. 



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 surface. They do not cause 

 liquefaction of the gelatin. 



If grown in slant- or stab-cultures, the surface-develop- 

 ment is very limited; along the needle-track tiny whitish 

 or bluish-white granules appear. 



On nutrient agar-agar the colonies are almost transparent, 

 more or less glistening, and very delicate in structure. 



On blood-serum development is more marked, though 

 still extremely feeble, appearing as a cluster of isolated fine 

 points growing closely side by side. 



Growth on potato is not usually observed. 



When grown in milk it commonly causes an acid reaction 

 with coincident coagulation of the casein. Some varieties, 

 especially non-virulent ones, do not coagulate milk.^ 



It is not motile. 



' Welch, loc. oit. 



