4 8 



Scientific Proceedings (55). 



quently washed to remove excess of hemolytic serum, that a hyper- 

 leucocytosis follows equalling in intensity the one produced in an 

 immunized animal. No such phenomenon occurs in a control 

 rabbit given sheep blood treated with the serum of a normal rabbit. 

 In other words, the marked leucocytic response in the immunized 

 animals is due to the tropic action of its serum on the antigen in 

 question. 



