286 PYOGENIC BACTERIA. 



the pus of acute abscesses, although it has heretofore only been found in as- 

 sociation with other microorganisms. 



4. MICROCOCCUS PYOGENES TENUIS. 



Obtained by Rosenbach (1884) from pus in three cases out of thirty- nine 

 examined. 



Morphology. Micrococci, somewhat irregular in size, but larger than 

 Staphylococcus albus, and seldom associated in masses. Frequently the in- 

 dividual cocci present the appearance of consisting of two deeply stained 

 masses separated from each other by a paler interspace. Cultures upon the 

 surface of nutrient agar form a very thin, transparent layer of about one 

 millimetre in breadth along the line of inoculation ; this resembles a thin 

 layer of varnish. 



Pathogenesis undetermined. (Micrococcus pneumonias crouposae ?) 



5. STREPTOCOCCUS PYOGENES. 



Synonyms. Micrococcus of erysipelas (Fehleisen) ; Streptococcus 

 erysipelatos ; Streptococcus of pus ; Streptococcus longus (Von Lin- 

 gelsheim). 



Obtained by Fehleisen from the skin involved in cases of erysipe- 

 las (1883), and by Rosenbach (1884) and Passet (1885) from the pus 

 of acute abscesses. The characters of the " streptococcus of erysipe- 

 las " of Fehleisen and the " Streptococcus pyogenes " of Rosenbach 

 and Passet are generally admitted to be identical, although some 

 bacteriologists still describe them separately and cultures from the 

 two sources are still retained in bacteriological laboratories under the 

 names originally given them. 



Rosenbach found Streptococcus pyogenes alone in fifteen cases, 

 and associated with staphylococci in five cases, out of thirty-nine 

 cases examined of acute pus formation. Passet, in thirty-three 

 similar cases, obtained the streptococcus alone in eight and associated 

 with staphylococci in two. Subsequent researches show that this 

 micrococcus is frequently, if not constantly, present in puerperal 

 metritis ; that it is the most frequent microorganism associated with 

 ulcerative endocarditis ; that it is frequently present in diphtheritic 

 false membranes, and especially in those cases of diphtheritic inflam- 

 mation which are secondary to scarlet fever and measles (Prudden). 

 Numerous investigations made by bacteriologists during the past few 

 years indicate that this is a very important and widely distributed 

 pathogenic microorganism. It has also been frequently found upon 

 exposed mucous surfaces mouth, nose, vagina of healthy in- 

 dividuals. 



According to the researches (1891) of Von Lingelsheim, the Strep- 

 tococcus pyogenes differs from Streptococcus erysipelatos in be- 

 ing pathogenic both for mice and rabbits, while the latter is patho- 



