PATHOGENIC BACTERIA. 139 



have not been found, though it is supposed because of their 

 permanency that spores are present, 



Properties. They are immotile, do not liquefy gelatine. 



Growth. They grow slowly, usually on the surface, and best 

 at higher temperatures. 



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

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

 scope, looking yellowish, finely granular, the edges quite defined. 



Stab Cultures. Along the needle-track little separated colonies 

 like strings of beads, which after a time become one solid white 

 string. 



Stroke Culture. Little drops, never coalescing, having a bluish 

 tint. 



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. 



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. 



In man, inoculations have been made to produce an effect 

 upon carcinomatous growths. Erysipelas was always produced 

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

 carditis results. Puerperal fever is caused by the microbe in- 

 fecting the endometrium, the Streptococcus puerperalis of Frankel 

 being the same germ. 



In scarlatina, variola, yellow fever, cerebro-spinal meningitis, 

 and many similar diseases, the microbe has been an almost con- 

 stant attendant. It is often associated with the diphtheria 

 bacillus in true diphtheria, and is the cause of many of the 

 diphtheritic affections of the throat in which the diphtheria 

 bacillus is absent. 



An antistreptococcic serum has been used as a curative 

 agent in puerperal fever, scarlatina, and other diseases sup- 

 posed to be due to this germ. 



A mixture of a culture of Pyogenes and Prodigiosus has been 



