On Tumor Immunity in Rats. 



33 



inflammation or reaction, if the grafts are made from a small, 

 non-necrotic tumor. 



2. Rats specifically immunized to the Flexner-Jobling adeno- 

 carcinoma respond to an implantation by an intense local in- 

 flammatory reaction, often with necrosis. 



3. Animals bearing necrotic tumors present this reaction on 

 reinoculation. 



4. After removal of the necrotic tumor, the animal still reacts 

 to reimplantation by local inflammation. 



These phenomena seem analogous to those instances of local 

 anaphylaxis known as the " Arthus " phenomenon in rabbits, and 

 to the local allergetic reactions described in human beings by 

 Pirquet. Until the possibility of a reaction to a complicating 

 infection of the tumor can be excluded (as suggested by Apolant 

 of Yamanouchi's experiments), this interpretation must be con- 

 sidered provisional. 



In the sarcomata of rats, it has not been possible to elicit 

 these phenomena. 



