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 

 microscopically. 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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