152 ANAPHYLAXIS 



gens, and that there does not exist a single precipitinogenic protein 

 which has not also anaphylaxis-producing properties. Precipitating 

 sera, moreover, always contain the anaphylactic-reaction product. 

 Whether or not special albuminolytic amboceptors may also be 

 concerned in the anaphylactic reaction must thus remain an open 

 question. So much is certain that precipitin formation and anaphyl- 

 actin formation evidently run a parallel course, and that there is 

 no good reason for doubting their identity. This, at least, seems 

 established for the anaphylactic reaction product which is formed 

 as the result of the parenteral introduction of albumins. In the case 

 of animal or vegetable cells, on the other hand, there is evidence 

 to show that the cytolytic amboceptors may play the role of the 

 anaphylactins. 



Complement and Production of Anaphylactic Toxin. That comple- 

 ment is necessary for the production of the anaphylactic toxin has 

 been demonstrated beyond a doubt. Friedemann and Friedberger 

 have thus shown that when fresh complement is added to a mixture 

 of an albumin and its corresponding antiserum, in the test-tube, a 

 toxic product (anaphylatoxin) is formed which, upon injection into 

 a suitable animal, calls forth practically all the characteristic symp- 

 toms of anaphylaxis. Quite in accord with this observation is the 

 fact that during the anaphylactic reaction, produced in the usual 

 w r ay, the complement of the blood is reduced to one-fifth or even 

 to one-half of the original amount, and that the shock cannot be 

 prevented by the artificial introduction from without of comple- 

 ment, even in large amount. Moreover, if an animal (such as the 

 pigeon) which is biologically far removed from the rabbit, and w^hose 

 complement does not supplement the action of any amboceptors 

 formed in the latter, is injected with the serum from a sensibilized 

 animal of this order, and then reinjected with the corresponding 

 antigen, no anaphylactic shock should theoretically develop, and, 

 as matter of fact, does not develop. As in the test-tube experiment, 

 furthermore, the action of complement can be prevented through 

 the addition of a suitable amount of salt, i. e., by raising the osmotic 

 pressure of the mixture; so, also, is it possible to prevent the develop- 

 ment of the anaphylactic shock in sensitized animals by a preliminary 

 injection of large amounts of salt. 



Nature of Anaphylactic Toxin. Regarding the nature of the ana- 

 phylactic poison, our knowledge is as yet quite meager. If we 



