STAPHYLOCOCCIC INFECTION 165 



by filtering old highly virulent cultures of the cocci, while the coccidal 

 agent is obtained by forming pleural exudates and separating the 

 remaining cocci by centrifugation. Evidently the phagocytes may be 

 strengthened in this contest in two ways. First, anything which will 

 improve their effectiveness will improve their chances, and second, 

 anything which will lessen the leukocidin of the cocci or render it inert, 

 will help the phagocytes. Vaccination as introduced by Wright is an 

 attempt to help the phagocytes in this contest. Within a limited field, 

 Wright's method of treating disease by vaccination has proved suc- 

 cessful. The best results have been secured in the treatment of such 

 pustular diseases as acne and furunculosis. In these diseases the cocci 

 are as it were entrenched and the phagocytes are slow to attack. By 

 injecting cocci into the midst of the leukocytes the latter are stimu- 

 lated through devouring easily the prey thus thrown to them. The 

 formation of bactericidal ferments by the phagocytes is improved by 

 exercise and this advantage brings victory to them. In the vaccine 

 treatment of disease there is always danger of overdoing the stimula- 

 tion of the leukocytes. It has worked better with pus bacteria than 

 with others, probably for the reason that the cocci protein is not rich 

 in poison. 



