319 



So with the rabbit 14i) aiitl 73 we do not timl a trace of active 

 immunisation, onlj of passive; rabbit 76 after 12 days shows a 

 small (active) increase of titre. The controlling rabbits however have 

 distinctly formed ambocej)tor. 



The second experiment with cattle corpuscles had a perfectly 

 analogous course. With these experiments we cannot inject intra- 

 venously; the animals which are intravenously injected with such a 

 great quantity of serum and corpuscles die of anaphylaxis. 



11. I have now put to myself the question what happens with 

 the sensitized corpuscles after the injection into the rabbit or cavia. 



Therefore I have for the time being con lined myself to the sub- 

 cutaneous resp. subconjunctive injection; the intravenous one is very 

 difficult to follow, the progress of the peritoneal one it mostly known ; 

 besides the subcutaneous is the only one that is to be considered 

 with regard to man. I expected that in keeping with what happens 

 in the peritoneum, viz. a solution of the sensitized red corpuscles 

 in a short time, the corpuscles would also dissolve in the subcuta- 

 neous tissue. I have taken the conjunctiva as the spot where to 

 inject: there the phenomena are to be controlled better than any- 

 where else, and one can easily cut out little pieces for microscopic 

 examination. 



Well then: if we inject foreign corpuscles under the conjunctiva 

 they are generally gone after one, and certainly so after two days. 



As they have no rao\ement of their own, we must assume them 

 to be led away along the lymphpaths — a leading away by phago- 

 cytes in such a short time is not to be assumed. It is however 

 different if sensitized corpuscles are injected ; these remain on the 

 spot; they do not dissolve in any quantity worth mentioning, and 

 if one microscopies the place after a longer or shorter space of time 

 (after cutting out, fixing, embedding, and colouring) one will find 

 an important number of leucocytes between the corpuscles. 



After 6 to 8 days only the corpuscles have generally disappeared; 

 sometimes however they are still to be seen after 10 to 12 days. 



During the first few days one mostly finds polynuclear small 

 leucocytes, later more great mononuclear ones. 



Now the question is how to explain this conduct. For this we 

 must examine three things. 



1st f{ow is it that the sensitized corpuscles which are injected 

 subconjunctively do not dissolve, while those injected intraperiton- 

 eal ly do. 



2nd Why do the sensitized corpuscles remain in the same place, 

 whereas the normal ones are carried away. 



