58 IMMUNITY 



ment being the really responsible potent factor in all these reactions 

 it may be assumed to have two binding affinities, one to the cells 

 which it designs to help and another effect upon antigen. If the 

 former be absorbed in any abnormal manner the latter is valueless. 



Cell Receptor and Immune bodies (follow figure 20). First Order: 

 Simple union of toxins (soluble) and fixed or free receptors or anti- 

 toxins; no complement needed. 



Second Order: Concerns agglutination and precipitation. Anti- 

 gen has two affinities, one for the haptophore of anti-body, another 

 for the agglutinin of the anti-body. The anti-body must therefore 

 have reversed corresponding fractions. The zymophore of anti- 

 body acts when the two haptophores have united and produced the 

 agglutination or precipitation. No complement is needed. 



Third Order: Concerns bacteriolysins, hemolysins or bacteroly- 

 sins, etc.; have haptophore for anti-body, and a toxophore. Anti- 

 body has haptophore for antigen and for the haptophore of the 

 complement. The union of the three must occur. Complement is 

 necessary for the destruction of the bacteria which it accomplishes 

 through its zymophore. 



Anaphylaxis. Against protection, the opposite of prophylaxis; 

 also called Hypersusceptibility. This phenomenon, first described 

 by Theobald Smith, Portier and Richet, consists in a condition of 

 extreme sensitiveness of animals against foreign proteins. If a 

 guinea pig be injected into the peritoneum with a minute quantity, 

 say jTnnr f a g ram ) f horses' serum and eight to ten days later 

 receive a quantity of j 1 ^ of a gram, the animal will become uneasy, 

 then depressed, have dyspnea, scratch itself violently about the 

 face and finally die after an intensification of these symptoms. 

 Similar symptoms have been observed in persons receiving diph- 

 theria anti-toxin therapeutically. The condition of high sensitivity 

 to this anti-toxin is called allergic and upon its degree depends the 

 reaction following anti-toxin administration. The skin eruptions, 

 joint pains and edema of serum sickness are also evidences of this 

 condition. It is said that those persons who suffer after anti-toxin 



