ANAPHYLAXIS 403 



central nervous system. If the antigen is injected slowly or in small 

 amount these sessile receptors are gradually united to antigen with- 

 out fatal shock, and the animal is thereby rendered insensitive. 



In his own words, this "desensitization" amounts to a return of 

 the cells to their normal preanaphylactic or naturally unsensitive 

 condition. With the refutation of his theory of anaphylaxis, his 

 theory of antianaphylaxis also falls to the ground, and neither of the 

 two can be accepted as valid at present. 



If we look upon anaphylaxis as a reaction taking place entirely in 

 the circulation we may accept, with Rosenau and Anderson 54 Fried- 

 berger, and others the explanation that antianaphylaxis is due to a 

 saturation of the anaphylactic antibody with antigen. Hypersus- 

 ceptibility is then subsequently reestablished because a gradual 

 formation &$. circulating antibody continues, and eventually free 

 antibody will again be present in the blood. This view is only in 

 part satisfactory, as Friedemann 55 points out. For it does not 

 explain the antianaphylaxis which Biedl and Kraus 56 have noticed 

 after the injection of mixtures of antigen and antibody, nor the non- 

 specific antianaphylaxis which the same workers have observed after 

 peptone injections. It is clear that the nature of antianaphylaxis 

 remains for the present obscure, and, in view of the recent attempts 

 to account for certain phases of infectious disease by the anaphy- 

 lactic phenomena, is one of the most important problems of im- 

 munity. 



Bearing upon this condition of antianaphylaxis is the tolerance 

 to the anaphylactic poison which has been observed to develop in 

 animals once or twice injected. Vaughan 5T has noticed this in ani- 

 mals injected with his toxic split products, produced by alkaline- 

 alcohol splitting of colon bacilli. By repeated injection of the guinea 

 pigs he showed that a tolerance was developed which protects the 

 animal from about double the fatal dose, but the animal is not pro- 

 tected against larger multiples, and the condition is not an immunity 

 in the sense in which we have used the term. Similar observations 

 have been made by Bessau. 58 Bessau passive sensitized guinea pigs 

 with 1 c. c. of anti-horse serum intraperitoneally, and on the follow- 

 ing day injected them intravenously with 1 c. c. of horse serum. He 

 gauged his dose so that the animals should have severe shock but 

 survive. One or two days later he injected the amount of typhoid 

 anaphylatoxin which was fatal for normal pigs, and found that those 



54 Rosenau and Anderson. U. S. Pub. Health and M. H. S. Hyg. Lab. 

 Bull., 64, 1910. 



55 Friedemann. "Frei Vereinigung f. Mikrobiol.," Berlin, 1910. Ref. 

 Centralbl. Bakt. I, Vol. 47; Beiheft, p. 1, 1910. 



56 Biedl and Kraus. Zeitschr. f. Imm., Vol. 4, 1910. 



57 Vaughan. "Protein Split Products, etc.," Lea & Febiger. Philadelphia, 

 1913, p. 139. 



58 Bessau. Centralbl. f. Bakt., Vol. 60, 1911. 



