CHAPTER XXVII. 
STREPTOCOCCUS PYOGENES (STREPTOCOCCUS ERYSIPE- 
LATUS ; STREPTOCOCCUS OF PUS ; STREPTOCOCCUS 
PATHOGENES LONGUS). 
THIS micrococcus was first observed by Koch in 
stained sections of tissues attacked by septic processes, . 
and by Ogston in the pus of acute abscesses (1882). 
It was obtained by Fehleisen (1883) in pure cultures 
from a case of erysipelas, its cultural and pathological 
characters studied and demonstrated by him to be 
capable of producing erysipelas in man. Rosenbach 
(1884) and Krause and Passet (1885) isolated the 
streptococcus from the pus of acute abscesses and gave 
it the name of streptococcus pyogenes. It has since 
been proved to be one of the chief etiological factors 
in the production of many suppurative inflammations. 
Formerly the streptococci of erysipelas, acute abscesses, 
septicemia, puerperal fever, etc., were thought to be- 
long to different species, because they were observed 
to possess apparent differences in their biological and 
pathological characteristics, according to the source 
from which they were obtained. Thus one species of 
streptococcus was believed to be capable of causing 
erysipelas only, another only acute abscesses, another 
sepsis, etc.; but it is now known that the slight differ- 
ences between the majority of the streptococci growing 
in long chains are but variations of one and the same 
