THE HUMORAL THEORIES OF ANAPHYLAXIS 591 



normal amboceptors, such as hemolysins, are present in normal serum, 

 so these protein amboceptors or albuminolysins may be present for 

 various proteins, explaining the production of the anaphylaxis poison 

 in vitro with a normal serum when the latter is fresh and active, i. e., 

 when complement is present. 



Theoretically, at least, it should be possible to detect the anaphy- 

 lactic amboceptor in a serum by a method of complement fixation, 

 although practically this is not the case. The whole subject of " fer- 

 ments" requires further study, and, as a result, our knowledge and views 

 of antibodies and the processes of immunity in general are likely to 

 undergo some change. 



The Humoral Theories of Anaphylaxis. With the foregoing explana- 

 tion of the chemical or humoral theory of anaphylaxis, I may briefly 

 summarize all the more important chemical or protein poison theories 

 advanced from time to time in explanation of the process. These 

 include the following: 



1. Richet held that the sensitizer, or anaphylactogen, contains a 

 substance which he called "congestion" (because he did his original 

 work with extracts of the tentacles of sea anemones, which are toxic 

 and produce congestion of the internal organs), and that this generates 

 in the animal another substance, known as the "toxogenin." The 

 reaction between the latter and the homologous protein on reinjection 

 sets free a poison, "apo toxin," which, because of its effect on the nervous 

 system, produces the symptoms of anaphylaxis. This theory is prac- 

 tically the same, as that generally accepted today, except that the anti- 

 gen is not of necessity primarily toxic for the animal. 



2. Hamburger and Moro suggest that the first injection leads to the 

 formation of precipitins, and that on reinjection precipitates are formed; 

 these they contend, may, by the formation of capillary emboli, produce 

 acute anaphylaxis, or atf least that precipitin formation runs parallel 

 with the antibody formation. The symptoms of anaphylaxis, however, 

 are not those of embolism, and there is no evidence to show that pre- 

 cipitation occurs in vivo, although, as Zinsser points out, precipitins may 

 play the role of sensitizers of the antigen, preparing them for final lysis 

 or cleavage by a complement. In other words, the precipitin would act 

 as an amboceptor, differing, however, from our general conception of 

 the nature of amboceptors by being active in the absence of complement, 

 unless precipitation is a secondary physical phenomenon in the nature 

 of a colloidal reaction. 



3. Besredka taught that the sensitizer contains two substances 



