1 68 The Story of the Bacteria 



opsonins by the body cells under the inspira- 

 tion of vaccines has been most effective in 

 infections by the pyogenic cocci. Though 

 called by the same name, these new " vaccines " 

 have nothing to do with the vaccine lymph 

 which is used to prevent small-pox. 



It is generally believed to-day that most of 

 the substances in the body fluids which kill 

 and destroy bacteria are furnished in part at 

 least by the leucocytes. So these doughty 

 defenders of the cell republic reach marauding 

 bacteria, not only when alive by personally 

 swallowing them, but by setting free germ- 

 killing stuff when they have succumbed. 



Based upon this knowledge of the effective 

 action of the leucocytes in setting free pro- 

 tective stuff, Dr. Hiss has proposed to secure 

 leucocytes in quantity from the lower animals 

 the rabbit for example, and to introduce 

 an extract of these into the bodies of persons 

 suffering from acute infections, thus rein- 

 forcing their capacity for resistance. 



This method of treatment is still under 

 investigation. But the reports of those who 

 have applied it in a variety of human in- 



