ANAPHYLAXIS OR HYPERSUSCEPTIBILITY 303 



taneously with its specific proteid, but only when the serum of the 

 sensitized animal precedes the injection of its antigen. This, he argues, 

 points to an anchorage of the sensitizing elements to the body cells 

 before an anaphylactic injury can occur. If the two substancse, 

 sensibilisin and antisensibilisin, meet in the blood stream, no harm 

 results, the elements neutralize each other and the animal is anti-ana- 

 phylactic. His contention that there are two separate elements, 

 sensibilisinogen and antisensibilisin, in the original proteid, is based on 

 the fact that sensitization can be accompHshed by sera heated to from 

 100° to 120° C, but that, after sensitization, no anaphylaxis results if 

 the injected serum be exposed previously to temperatures of 100° C, 

 and the reaction is rendered much less violent even by exposure of sera 

 to temperature of 50 to 60° C. 



Recently an attempt has been made to associate the phenomena of 

 anaphylaxis with the formation of precipitates. Hamburger' early ex- 

 pressed the opinion that anaphylaxis may be nothing more than the for- 

 mation of emboli by serum precipitates. This view, however, has found 

 few adherents in face of the facts that we have no positive evidence 

 of the actual occurrence of precipitates in the blood streams of living 

 animals, and that it has been shown by Friedemann^ that the precipitates 

 produced in vitro will, when injected intravenously in animals, pass 

 through the capillaries without harmful effects. 



Doerr and Russ,' on the other hand, have recently studied carefully 

 the relationship between anaphjdaxis and the precipitin reaction and 

 have shown a close parallelism between the two. These observers in- 

 jected rabbits with precipitating antisera and twenty-four hours later 

 treated the same animals with the antigen employed for the production 

 of these precipitating sera. They found that, in such experiments, the 

 regularity of occurrence and degree of anaphylaxis which ensued, were 

 directly proportionate to the precipitating powers of the serum first 

 injected. They claim, from such results, that precipitable antigen and 

 anaphylactic antigen are identical substances. They conceive the phe- 

 nomenon of anaphylaxis as a reaction between precipitins, attached 

 to the tissue cells, and the precipitable antigen. In other words, the 

 anaphylactic shock is looked upon as an intracellular precipitin reaction. 



Friedberger and Hartoch* have recently called attention to another 



> Hamburger, quoted by U. Friedemann, Zeit. f. Immunitatsforsohung, ii, 1909. 

 = Friedemann, loc. cit. 



• Doerr and Russ, Zeit. f . Immunitatsforschung, iii, 1909. 



* Friedberger und Hartoch, Zeit. f. Immunitatsforschung, iii, 1909. 



