ANAPHYLACTIN (ALLERGIN) 553 



though, instead of being protective to the animal, its host, it is just the 

 reverse. Richet named it toxogen, because it is responsible for the pro- 

 duction of a poison. Otto speaks of it as "reaction body, " Nicolle as an 

 albuminolysin, Besredka as sensibilisin, and von Pirquet as allergin. 



Nature of Anaphylactin. A full discussion of the nature of this body, 

 which is believed to cleave the anaphylactogen and set free the anaphy- 

 latoxin or protein poison, would involve a review of the entire subject 

 of antibodies and immunity in general. Vaughan regards it as a ferment, 

 evidently meaning that an amboceptor and a complement act together 

 and produce lysis or disruption of the protein molecule. It is difficult, 

 and indeed impossible, at this time to discuss with any degree of definite- 

 ness the propriety of regarding an immune and cytolytic amboceptor 

 as a ferment, just as we regard trypsin as a ferment. If the ferments 

 are to be considered as identical with amboceptors, then we must regard 

 Abderhalden's protective ferments as cytolysins, but certainly, in the 

 light of our present knowledge, we are hardly justified in drawing hard 

 and fast lines. Therefore while I have confined the discussion of the 

 protective ferments to a separate chapter (Chapter XV), and have not 

 considered it under the general head of the cytolysins, it is to be 

 remembered that the ferments possess many of the properties of lytic 

 amboceptors, and they may be identical with them although apparently 

 different owing to the application of chemical methods, especially by 

 Abderhalden, in their study. 



Most observers regard the anaphylactic antibody, toxogen or allergin, 

 as an amboceptor and a complement. The actual antibody then must 

 be considered as an immune albuminolysin, for complement is present 

 in normal serum, and is not necessarily increased during the process of 

 sensitization. As in other lytic processes, however, complement or 

 alexin is of great importance, constituting, as it does, the actual lytic 

 agent, after the antigen, or, in this instance, the anaphylactogen of the 

 second injection, has been sensitized by the amboceptor. Some ob- 

 servers believe that the complement is decreased during anaphylaxis, 

 presumably being used up in effecting lysis of the protein. Friedmann 

 claims that in allergy to red corpuscles there is a close parallelism between 

 the anaphylactic bodies and the hemolytic amboceptor. 



With the more recent work of Abderhalden on protective ferments 

 and the development of a dialysis and optical method of detecting the 

 products of protein cleavage, it was hoped that the true and exact nature 

 of anaphylaxis would finally be established. It would appear possible 

 to determine the presence, in the blood-serum of sensitized animals, of 

 specific proteolytic ferments capable of demonstrating their presence 



