142 



MICRO-ORGANISMS AND DISEASE [chap. 



when cultivated prove to belong to two well-defined species : 

 staphylococcus pyogenes aureus and albus. 



Staphylococcus pyoge?ies aureus. — This organism is com- 

 mon in acute suppurations and ulcerations, alike those 

 in the skin or mucous membranes, serous membranes, or 

 parenchymatous organs ; it is met with abundantly also in 

 acute external imflammations, ulcerations {e.g. after vaccinia 



Fig. 32. — Film Specimen of Peritoneal Exudation of a Guinea-pig, dead 

 FROM Acute Peritonitis after Intraperitoneal Injection of Culture 

 of Staphylococcus Aureus. 



Four lymph-cells filled with the cocci. X icxx). 



and variola, in diphtheritic inflammation of the fauces, 

 in some cases of ulcerative endocarditis). In purulent in- 

 flammations (abscesses acute and chronic) this organism is 

 present in large numbers in the pus as single cocci, as 

 dumb-bells, and as large and small connected clusters. 

 Many of the dumb-bells and connected masses show the in- 

 dividuals as crescents — that is as divided. A film of pus dried 

 on a cover-glass, heated and stained in methyl-blue or gentian 



