298 STUDIES IN IMMUNITY. 



should take up alexin energetically in the same way as sensitizer 

 plus corpuscle does. This is not found to be true.* 



To sum up: first, the antisensitizer unites with the sensitizer 

 already fixed on the specific corpuscles, which latter it cures; second, 

 the antiserum owes its activity to a single unique substance that 

 endows it with the property of protecting various sensitized cells; 

 in other words, of neutralizing various sensitizers that combine each 

 with a different type of receptor; for example, the same antisensi- 

 tizer combines not only with rabbit > ox sensitizer, but also with 

 other normal or specific sensitizers that do not unite with ox cor- 

 puscles; third, the antisensitizer removes from sensitized corpuscles 

 their power of absorbing alexin. All the facts appear to be irrecon- 

 cilable with Ehrlich's theory, and tend to prove the general thesis 

 that antitoxins (or other antibodies) are not assimilated by the recep- 

 tors that fix their respective toxins. We consider them all, whether 

 acting against bacterial, vegetable or animal" toxins, as substances 

 of the same nature and of a common cellular origin, in the same gen- 

 eral category and with marked similarity. If the receptor theory 

 were true, the various antitoxins would be united by no analogy, 

 since it would seem reasonable that the receptors attacked by 

 various toxins must be widely different, according to the nature 

 and property of the poison in question. 



Ehrlich and Morgenroth have given over the larger part of one 

 memoir to a consideration of the antisensitizers,f the importance 

 of which is essential to partisans of the lateral-chain theory. This 

 article, indeed, is one of those that have most contributed to make 

 this conception acceptable and to offer the most convincing argu- 

 ments of its accuracy. The facts brought forth in this article are 

 in direct opposition to our own and must, therefore, be considered. 

 We shall first of all, however, deal with an article recently published 

 by Morgenroth 4 



* If we were to accept the ideas of the Ehrlich school, and particularly the 

 ideas that the sensitizer combines with the alexin and that each property mani- 

 fested by a substance is evidenced by a particular grouping in the molecule, one 

 might say that the antisensitizer should unite only with the cytophilic group of 

 the sensitizer and not with its complementophilic group. There is no experi- 

 mental evidence for this. 



t Studies on Immunity, Ehrlich-Bolduan, John Wiley and Sons, p. 88. 



t Morgenroth, Komplementablenkung durch hamolytische Ambozeptoren. 

 Centralblatt fur Bakt., XXXV, 1904, 501. 



