fi41 



Von Düngkrn lias described a single cxperinieiu about llic immii- 

 iiisation power of red corpuscles of the ox, loaded with amboceptor, 

 upon the rabbit. In his experimenting he found as good as no am- 

 boceptor formation. 



Sachs has extended these experiments, and he found that the 

 amboceptorformation was a less good one, but that it certainly did 

 exist. He too communicates but one series of experiments with corpus- 

 cles saturated to a maximum. 



I here do not wish to show the differences between Besrkdka's 

 experiments and those of the Germans; this I will do in a following 

 communication. But for me (his controversj' was enough reason to 

 get some more insight into this question by more extensive experi- 

 ments. Besides, one argument caused me not to consider of general 

 ^■alue the result which the German investigators drew from their 

 experiments, viz. that antigens loaded with antibodies possess no or 

 very little immunisation power. 



For it is a wellkuown fact that, in order to get an immuneserum 

 with a high titre, one must inject antigen in question more than 

 once. The second and following injections are generally given to 

 an animal that already possesses a certain quantity of antibody, 

 even more than is necessary, to saturate the quantity of antigen 

 which is being injected. Now there is not so very much ditference 

 between treating an animal for the second time, and injecting antigen -}- 

 antibody at the same time into a non treated animal. And from the 

 fact that a second injection of a previousl}^ treated animal does 

 possess immunisation power, I considered the opinion of v. Düngern 

 c.s. improbable. 



Suchlike experiments have been made by Dj'. TmELE according to 

 a communication given by him during a discussion in the bactereo- 

 logical section of the international congress in London. Then my 

 experiments were already in progress. 



1 started studying the origin of antibodies in rabbits after the 

 injection of heterogeneons red corpuscles loaded more or less with 

 amboceptor. I have especially taken care also to use red corpuscles, 

 loaded with little amboceptor, because it was possible that this would 

 furnish a clue to solve the difference. 



As to the technic of the experiments see below : 



A great number of rabbits (15 — 18) were always injected with 



foreign red corpuscles at the same time. The rabbits had never been 



treated with the kind of blood in question before. With my later 



experiments the animals were always first weighed and injected in 



