CHAPTER XVI. 



Suppuration— The staphylococcus pyogenes aureus— Staphylococcus pyo- 

 genes albus and dtreus— Streptococcus pyogenes— Bacillus pyocyanus— Gen- 

 eral remarks. 



Prepare from the pus of an acute abscess or boil, 

 that has been opened under antiseptic precautions, a 

 set of plates of agar-agar. Care must be taken that 

 none of the antiseptic fluid gains access to the culture 

 tubes, otherwise its antiseptic effect may be seen and 

 the development of the organisms interfered with. It 

 is best, therefore, to take up a drop of the pus upon the 

 platinum-wire loop after it has been flowing for a few 

 seconds ; even then it must be taken from the mouth 

 of the wound and before it has run over the surface of 

 the skin. At the same time prepare two or three cover- 

 slips from the pus. 



Microscopic examination of these slips will reveal 

 the presence of a large number of pus-cells, both multi- 

 nucleated and with horseshoe-shaped nuclei, some 

 threads of disintegrated and necrotic connective tissue, 

 and, lying here and there throughout the preparation, 

 small round bodies which will sometimes appear- singly, 

 sometimes in pairs, and frequently will be seen grouped 

 together somewhat like clusters of grapes. (See Fig. 

 45.) They stain readily and are commonly located in 

 the material between the pus-cells ; very rarely they 

 may be seen in the protoplasmic body of the cell. 

 (Compare the preparation with a similar one made 

 from the pus of gonorrhoea — see Fig. 46. In what 



