140 ESSENTIALS OF BACTERIOLOGY. 



used as an injection, with apparent benefit, in inoperable cases 

 of sarcoma. 

 Staphylococcus Pyogenes Aureus. (Rosenbach.) 



FIG. 76. 



Staphylococcus pyogenes albus (Jakob). 



Origin. Found commonly in pus (80 per cent, of all suppura- 

 tions), in air, water, and earth ; also in sputum of healthy persons. 



Form. Micrococci in clusters like bunched grapes, hence the 

 name staphylo, which means grape. They never form chains. 

 Spores have not been found, though the cocci are very resistant. 



Properties. Without movement ; liquefying gelatine. It gives 

 rise to an orange-yellow pigment in the various cultures. 



Growth. It grows moderately fast at ordinary temperature, 

 and can live without air, a facultative serobin and anierobin. 



Colonies on Gelatine. On second day small dots on the surface, 

 containing in their centre an orange-yellow spot. The gelatine 

 all around the colony is liquefied ; the size is never much greater 

 than that attained the second day. 



Colonies on Agar. The pigment remains a long time. 



Stab Culture. At first, gray growth along the track, which, 

 after three days, has settled at the bottom of the tube in a yel- 

 low granular mass, the gelatine being all liquid. 



Stroke Culture on Agar. The pigment diffused over the sur- 

 face where the growth is, in moist masses. 



