466 BACTERIOLOGY. 
vein of a pure culture of staphylococcus aureus gives 
rise to a genuine ulcerative endocarditis. It has been 
further shown by Ribbert that the same result may be 
obtained without previous injury to the valves by in- 
jecting into a vein the staphylococcus from a potato 
culture suspended in water. In his experiments not 
only the micrococci from the surface, but the super- 
ficial layer of the potato was scraped off with a steril- 
ized knife and mixed with distilled water, and the 
successful result is ascribed to the fact that the little 
agglomerations of micrococci and infected fragments of 
potato attach themselves to the margins of the valves 
more readily than isolated cocci would do. Not infre- 
quently, also, in intravenous inoculations of young ani- 
mals there occurs a localization of the injected material 
in the marrow of the small bones. This may take place 
in full-grown animals when the bones have been injured 
or fractured. The experimental osteomyelitis thus pro- 
duced has been demonstrated to be anatomically analo- 
gous to this disease in man. With regard to the lesions 
found in the kidneys after intraperitoneal or intravenous 
inoculation of cultures of the staphylococcus, it has been 
found that when injected in considerable quantities the 
organism may be obtained in cultures from the urine, 
but not sooner than six or eight hours after the injec- 
tion, and not until the formation of purulent foci in 
the kidneys has already occurred. 
The Production of Toxic Substances. The peculiar 
energetic action of the staphylococcus pyogenes aureus 
on the tissues of warm-blooded animals would seem 
to indicate that toxic substances are produced by 
this organism, which play an important part in its 
infective properties. Grawitz and De Bary have 
