PYOGENIC COCCI 165 



Colonies. In three days a very small grayish speck, which 

 hardly ever becomes much larger than a pin-head; under 

 microscope, looking yellowish, finely granular, the edges well 

 defined. 



Stab-cultures. Along the needle-track little separated col- 

 onies, like strings of beads, which after a time become one 

 solid white string. 



Stroke-culture on A gar. Little drops, never coalescing, 

 having a bluish tint, very transparent. 



Potato. No apparent growth. 



Bouillon. At 37 C. clouds are formed in the bouillon, 

 which then sink to the bottom, and long chains of cocci found 

 in this growth. 



Lqffler's Blood-serum and Serum Bouillon. Development 

 more abundant in serum media. 



Milk. Good growth; produce lactic acid and coagulate 

 milk. 



Preservation of Cultures. In ice-chest, the cultures may be 

 kept alive several weeks at room temperature; they usually 

 die out in ten days. 



Staining. Easily colored with the ordinary stains. Gram's 

 method is also applicable. 



Pathogenesis. Inoculated subcutaneously in the ear of a 

 rabbit, an erysipelatous condition develops in a few days, 

 rapidly spreading from point of infection. 



The micro-organism acts variously, depending upon the 

 nature of the lesion from which it originally was obtained. 

 Injected into the circulation, septicemia results. The more 

 virulent the affection, the more virulent the strain. 



In man, inoculations have been made to produce an effect 

 upon carcinomatous growths, and erysipelas has always re- 

 sulted. When it occurs upon the valves of the heart, endo- 

 carditis results. Puerperal fever is caused by the microbe 

 infecting the endometrium, the Streptococcus puerperalis of 

 Frankel being the same germ. 



In scarlatina, variola, yellow fever, cerebrospinal menin- 

 gitis, and many similar diseases, the microbe has been an 



