HYPERSUSCEPTIBILITY 357 



with a few commentaries and slight modifications, as follows: "The 

 observed toxicity of the injected material must depend upon sen- 

 sitization of the animal, that is, the substance must not produce 

 similar symptoms in the non-sensitized animal" (of the same 

 species). "It should be possible to demonstrate passive sensitization 

 with the serum of a sensitized animal. ' ' This we would modify some- 

 what since, of course, in the early stages of developing hypersus- 

 ceptibility, an animal, though sensitive, may have but slight or even 

 no demonstrable antibodies in his serum. It would perhaps be more 

 accurate to say that it must be possible to produce passive sensitiza- 

 tion to an antigen by the administration of serum which contains 

 antibodies to this antigen. If dealing with guinea pigs, it should be 

 possible by the Dale Method, to demonstrate typical reactions as 

 described below with the uterus of the sensitized guinea pig. After 

 recovery from anaphylactic shock, a condition of desensitization 

 should be apparent if quantitative conditions are taken into account. 

 This is not all that Wells says about it, and we have somewhat 

 modified it for our own purposes, but, in general, these criteria are 

 the chief ones which must be met, and they all boil down to the 

 statement that, in order to be considered true aiiaphylaxis, it must 

 be shown that the mechanism of whatever reaction that may occur 

 is one that is fundamentally based upon the meeting of an antigen 

 with its homologous antibody. Further limitations of this, as to the 

 site and manner of such meeting will be described below. 



THE ANAPHYLACTIC ANTIGEN. We may save much discussion for 

 the purposes of this particular book by saying that substances with 

 which true aiiaphylaxis can be produced are all, as far as we know, 

 protein in nature. No conclusive proof has ever been brought that 

 lypoids or carbohydrates can act as antigens, and work with protein- 

 split products has not been sufficiently satisfactory. Racemized 

 proteins have been shown by Ten Broeck 21 not to exert antigenic 

 action for anaphylaxis. Wells, himself, states that he has always 

 obtained negative results with protein cleavage products, but says 

 that Fink 22 in his own laboratory has occasionally obtained slight 

 anaphylactic reactions with proteose fractions obtained from 

 coagulated egg-white by hydrolysis with steam under pressure, for 

 those parts of the proteose solution which were precipitated by 



21 Ten Eroeck, Jour. Biol. Chem., 17, 1914, 369. 



22 FinTc, Jour. Inf. Dis., 25, 1919, 97. 



