336 



PATHOGENIC ORGANISMS 



Pure cultures of streptococci were first obtained by Fehleisen 1 in 1883 

 and by Rosenbach 2 in 1884. The thorough and systematic researches of 

 the last-named authors, together with those of Passet, 3 were of special 



^ I 



# V 





FIG. 72. STREPTOCOCCUS PYOGENES. 



influence in placing our knowledge of the pathogenic properties of 

 streptococci upon a scientific basis. 



Morphology and Staining. The individual streptococcus is a spherical 

 microorganism measuring from 0.5 micron to 1 micron in diameter. 

 Since the line of cleavage of cocci, when in chains, is perpendicular to the 



, " Aetiol. d. Erysipelas," Berlin, 1883. 



2 Rosenbach, " Mikroorg. bei Wundinfektion," etc., Wiesbaden, 1884. 



3 Passet, " Untersuch. tiber die eitrigen Phlegm.," etc., Berlin, 1885. 



