1 88 PA THOGENIC BA CTERIA . 



of color-production, so that the centre of the growth is 

 distinctly golden ; the edges may be white. 



Upon potato the growth is luxuriant, producing an 

 orange-yellow coating over a large part of the surface. 

 The potato-cultures give off a sour odor. 



When grown in bouillon the organism causes a diffuse 

 cloudiness. 



In milk coagulation takes place, and is followed by 

 gradual digestion of the casein. 



The Staphylococcus albus is exactly the same as the 

 aureus, with the exception that in all media it is con- 

 stantly colorless. 



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 

 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 

 tufts of the kidneys sometimes are full of cocci, and 

 become the centres of small abscesses. 



The coccus is almost equally pathogenic for man, 

 though the fatal outcome is much more rare. It enters 

 the system through scratches, punctures, or abrasions, 

 and when virulent generally causes an abscess, as various 

 experimenters who inoculated themselves have discov- 

 ered to their cost. Garre applied the organism in pure 

 culture to the uninjured skin of his arm, and in four 

 days developed a large carbuncle with a surrounding 



