680 COLLECTED STUDIES IN IMMUNITY. 



of antitoxin sufficient to neutralize one million times the quantity of 

 toxin injected. 



There are those, to be sure, who believe the process is much 

 simpler than this. Straub, for example, thinks it is essentially 

 analogous to simple detoxicating phenomena occurring in the body, 

 comparing it, for example, with the formation of an ethereal sul- 

 phuric acid from injected phenol. The only difference, Straub 

 believes, is that phenol sulphuric acid is stable in the organism, while 

 the toxin-antitoxin combination is unstable, being partially destroyed 

 in the organism. This destruction, however, affects only one com- 

 ponent, the injected toxin, the other, the reaction product of the 

 organism (being related to the organism and therefore not a foreign 

 biological substance) escapes elimination and remains in the blood 

 and body fluids. By systematically repeating the poisoning it is 

 thus possible to increase the protective power of the blood, so that 

 when this blood is injected into other animals the protective power 

 is transformed, and the injected animals become resistant to the 

 toxic infection. 



This is Straub's idea. With so simple an explanation, one will 

 wonder why this question has engaged the attention of so many 

 investigators in immunity these many years. As a matter of fact, 

 however, it seems entirely to have escaped the author that according 

 to his theory a certain quantity of toxin can only produce an equiv- 

 alent amount of antitoxin. Fortunately, however, in immuniza- 

 tion this is not the case. It can be shown, as has already been said, 

 that one part of toxin can produce an amount of antitoxin a million 

 times more than the equivalent. This alone is enough to show 

 how untenable Straub's conception is. 



Of far greater importance is the fact that the demonstration of 

 this hyperregeneration proves the preformation and the chemical 

 individuality of the corresponding toxin receptors. That which the 

 cell constantly produces and which can be given off to the blood after 

 the manner of a secretion must have a chemical "individuality." 

 This constitutes the first step toward resolving the cell concept into 

 a large number of separate individual functions. From the begin- 

 ning I had assumed that the toxin represented nothing more than an 

 assimilable food stuff to which in addition, by chance as it were, was 

 attached a side group, very labile in character, which really exerted 

 the toxic action. 



This view was very quickly confirmed in a number of ways. 



