CHAPTER XXI. 



Suppuration The staphylococcus pyogenes aureus. 



PKEPAEE from the pus of an acute abscess or boil, 

 which has been opened under antiseptic precautions, a 

 set of plates of agar-agar. Care must be given 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 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 

 after the manner of clusters of grapes. They stain 

 readily and are commonly located in the material be- 

 tween 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. In 

 what way do the two preparations differ the one from 

 the other?) 



