Facts bearing on acquired immunity 249 



gocytic reaction is the only one that can be said to be constant. We 

 find it in those examples in which the influence of the fluids of the 

 body is most manifest, as in the experimental cholera peritonitis of 

 the guinea-pig, as well as in those cases where the humoral action is 

 most feeble, as in anthrax or in the Trypanosoma disease of rats. 

 \Ve have, however, still to establish the relations that exist between 

 phagocytosis and the part played by the fluids of the immunised 

 animal, in order that we may, as far as possible, present a general 

 picture of the inner mechanism of acquired immunity against micro- 

 organisms. To attain this result we must place the reader in posses- [262] 

 sion of further well-established facts, and we must postpone its 

 discussion to the following chapter, which will be entirely devoted 

 to the above-mentioned problem. 



