HISTORIC DEVELOPMENT OF IMMUNOLOGY 69 



The Bleeding When a suitable stage of im- 

 munization has been reached the horse is bled 

 and the utmost care is taken to attain asepsis : 

 all instruments, vessels, and apparatus are 



Jules Bordet. 



thoroughly sterilized after approved methods. 

 A sterile canula is inserted into the jugular 

 vein and the blood allowed to flow into large, 

 sterile glass vessels containing sodium citrate 



