38 EXPERIMENTAL RESEARCHES 



bacteria. The possibilities which I have here 

 indicated appear to be limitless, and the need 

 for study in this direction is evident. 



I would here express my dissent from a pre- 

 judice which often makes itself felt, to the effect 

 that in this matter there exists a profound con- 

 tradiction between humoral and cellular im- 

 munity. As a matter of fact, to assume that 

 the action of antibodies is merely a process 

 of humoral pathology, is to put an artificial 

 construction on the facts observed : for the 

 side-chain theory is founded upon the view that 

 the antibodies are purely and simply the pro- 

 duct of cellular secretion, and that with their 

 appearance in the blood there are associated 

 changes in the cells which correspond to the 

 phenomenon of serum immunity. That the 

 action of antibodies takes place in the juices of 

 the organism is an incontestable fact, which, 

 however, in view of the cellular processes which 

 give rise to it, cannot with justice be claimed to 

 be evidence in proof of the correctness of 

 humoral pathology, otherwise we must consider 

 the action of ferments to be one of humoral 

 physiology. 



In the Protean forms of the phenomena of im- 

 munity, of course, the action of haptines by no 



