252 



PATHOGENIC BACTERIA. 



Experiments have shown that the Staphylococcus 

 aureus, like its congener, the albus, exists in an atten- 

 uated form, and there is every reason to believe that in 

 the majority of instances it inhabits the surface of the 

 body in that condition. 



When virulent the golden staphylococcus is a danger- 

 ous and often deadly organism. Its pathogeny among 

 animals is decided. When introduced subcutaneously, 

 abscesses almost invariably follow, except in a certain 



Fig. 53. — Staphylococcus pyogenes aureus : puncture-culture three days old 

 in gelatin (Frankel and Pfeiffer). 



few comparatively immune species, and not infrequently 

 lead to a fatal termination. In such cases the organisms 

 may be cultivated from the blood of the large vessels, 

 though by far the greater number collect in, and fre- 

 quently obstruct, the capillaries. In the lungs and 

 spleen, and still more frequently in the kidneys, infarcts 

 are formed by the bacterial emboli. The Malpighian 



