CHAPTER XXVI. 
THE PRODUCERS OF ABSCESS, CELLULITIS, SEPTI- 
CHMIA, ETC. 
THE STAPHYLOCOCCI. THE MICROCOCCUS 
TETRAGENUS. 
The Staphylococcus Pyogenes Aureus. (The Golden 
Staphylococcus.) 
THE staphylococcus pyogenes aureus is one of the 
commonest pathogenic bacteria, being almost every- 
where present, and is the organism most frequently 
concerned in the production of acute, circumscribed, 
suppurative inflammations. It was first observed by 
Ogston (1881) in the pus of acute abscesses, but was 
not obtained by him in pure culture. It was isolated 
from the pus of acute abscesses and accurately described 
by Rosenbach (1884). 
Morphology. Small, spherical cells, having a diameter 
of 0.87 (Passet), occurring solitary, in pairs as diplo- 
cocci, in short chains of three or four elements, or in 
groups of four, but most commonly in irregular masses, 
simulating clusters of grapes; hence the name staphylo- 
coccus. (See Fig. 59.) 
It stains quickly in aqueous solutions of the basic 
aniline colors. When previously stained with methyl- 
violet it is not decolorized by Gram’s method. 
Biology. The staphylococcus pyogenes aureus is an 
aérobic, facultative anaérobic, liquefying micrococcus, 
