14 EXPERIMENTAL RESEARCHES 



lactic purposes we inject an antitoxic serum, 

 the number of receptors in the organism fitted 

 for union with the poison is increased, the 

 quantity of receptors introduced being charac- 

 terised by the fact that, as antitoxins, they 

 represent dissolved cell contituents, which, by 

 their union with the toxin, can do no harm, but 

 by their presence in considerable quantity bring 

 about a marked change in the conditions of 

 distribution in the organism. The receptors of 

 the organs which are sensitive to the action 

 of the poison are reinforced by a large number 

 of free antitoxin receptors, which, by reason of 

 the factor of distribution, and also because they 

 take up the toxin in the juices of the organism, 

 bring about this condition of affairs. The toxin 

 is thus either kept away from the organs which 

 it threatens to attack, or it comes in contact 

 with them only in an inconsiderable amount, 

 and so the disease runs a favourable course. 

 Of course the toxin, which has already become 

 united to the cell, and has exerted a deleterious 

 influence upon it, cannot be rendered innocuous ; 

 for we know that in all reactions of a similar 

 nature observed in the study of immunity, 

 primary union is followed by a stage of 

 secondary consolidation, a stage in which, even 



