STAPHYLOCOCCUS PYOGENES 

 AUREUS AND ALBUS 



IN the pus from a large proportion of abscesses, 

 boils, pustules, and other similar suppurative foci 

 will be found either the Staphylococcus Pyogenes 

 Aureus or Albus the former the more frequently. 

 These two organisms resemble one another closely, 

 and, indeed, might be regarded as identical, but that 

 cultures of the former produce a golden yellow pig- 

 ment wanting in the latter. In pus (Fig. 46) the 

 staphylococci occur as irregular, usually small groups 

 of spherical cells lying free in the fluid. The indi- 

 vidual cells measure *8 p in diameter, and are easily 

 stained by basic dyes and by Gram's method. From 

 pus containing them the staphylococci are very 

 readily cultivated on any of the ordinary nutrient 

 media, and at temperatures between 14 C. to 42 C. 

 They are facultative anaBrobes. On agar they form 

 copious, thick, opaque, moist growths resembling a 

 streak of oil paint, yellow in the case of Staphylo- 



