STREPTOCOCCUS PYOGENES 359 



It is a facultative anaerobe. 



It stains with the ordinary aniline dyes, and is not decolor- 

 ized when subjected to Gram's method. 



It is not motile. Under artificial conditions we have no 

 reason to believe that it enters a stage in which its resis- 

 tance to detrimental 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 inflammatory 

 conditions due to this organism, often at a relatively long 

 time after the primary site of infection has healed. 



Such in general will serve to identify the streptococci 

 concerned in the disease.. 



Streptococcus pyogenes is the organism most commonly 

 found in rapidly spreading suppurations, while micrococcus 

 aureus is most frequently found in circumscribed abscess 

 formations; they may also be found together, and these 

 relationships may be reversed at times. 



The results of its inoculation into the tissues of lower 

 animals are described by Rosenbach and Passet as pro- 

 tracted, progressive, erysipelatoid inflammations; and 

 Fehleisen, who first described a streptococcus in erysipelas 

 that is closely related to the Streptococcus pyogenes under 

 consideration, stated that it produced in the tissues of 

 rabbits (the base of the ear) a sharply defined, migratory 

 reddening without pus formation. The writer encountered 

 a strain 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. In one animal these conditions 

 appeared simultaneously. This observation has an impor- 

 tant bearing upon the question concerning the identity of 

 streptococci found in various inflammatory conditions, such 



