280 BACTERIOLOGY. 



mental agencies is increased. In the tissues of the 

 body, however, it appears to possess marked vitality, 

 for it is not rare to observe recurrences of inflam- 

 matory conditions due to this organism, often at a 

 relatively long time after the primary site of infection 

 has healed. 



Streptococcus pyogenes is the organism most commonly 

 found in rapidly spreading suppurations, while micro- 

 coccus aureus is most frequently found in circumscribed 

 abscess formations ; they may also be found together. 



The results of its inoculation into the tissues of 

 lower animals are described by Rosenbach and Passet 

 as protracted, progressive, erysipelatoid inflammations; 

 and Fehleisen, who described a streptococcus in erysip- 

 elas that is in all probability identical with the strepto- 

 coccus pyogenes under consideration, stated that it pro- 

 duced in the tissues of rabbits (the base of the ear) 

 a sharply defined, migratory reddening without pus- 

 formation. The writer has encountered a culture of 

 this organism that possessed the property of inducing 

 erysipelas when introduced into the skin of the ear, and 

 disseminated abscess-formation when injected into the 

 circulation of rabbits. This observation has an im- 

 portant bearing upon the question concerning the iden- 

 tity of streptococci found in various inflammatory con- 

 ditions, such, for instance, as the spreading erysipelatoid 

 manifestations on the one hand, and the circumscribed 

 abscess-formations on the other. 



The results that follow upon the inoculation of ani- 

 mals with cultures of streptococci obtained from various 

 inflammatory lesions are, as a rule, inconstant. At 

 times cultures will be encountered that are apparently 

 without virulence, no matter how tested ; while again 



