PRODUCERS OF ABSCESS, CELLULITIS, ETC. 465 
ject, when injected subcutaneously in large quantities 
(several c.c. of a fresh bouillon culture) in rabbits or 
guinea-pigs, give rise to local pathological lesions—acute 
abscesses. When virulent cultures are used—which are 
rarely obtainable—0.5 c.c. of a fresh bouillon culture 
is sufficient to produce similar results. The abscesses 
heal generally without treatment; sometimes the ani- 
mals die from marasmus in consequence of the sup- 
purative process. In intraperitoneal inoculations the 
degree of virulence of the culture employed is still 
more conspicuous in the effects produced. The ani- 
mals usually die in from two to nine days. The most 
characteristic pathological lesions are found in the kid- 
neys, which contain numerous small collections of pus, 
and under the microscope present the appearances 
resulting from embolic nephritis. Punctiform, whitish- 
yellow masses of the size of a pea are found permeating 
the pyramids. Many of the capillaries and some of the 
smaller arteries of the cortex are plugged up with 
thrombi consisting of micrococci. Metastatic abscesses 
may also be observed in the joints and muscles. The 
micrococci may be recovered in pure cultures from the 
blood and the various organs; but they are not numer- 
ous in the blood and are often difficult to demonstrate 
Inicroscopically. Intravenous inoculations of animals 
are followed by similar pathological changes Orth 
and Wyssokowitsch first pointed out that injection of 
staphylococci into the circulation, after injuring the 
cardiac valves in rabbits, produced ulcerative endo- 
carditis. Subsequently, Weichselbaum, Prudden, and 
Fraenkel and Sanger obtained confirmatory results, 
thus establishing the fact that when the valves are first 
injured, mechanically or chemically, the injection into a 
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