56 IMMUNITY 



The production of bacteriolysins is explained by Ehrlich's lateral- 

 chain hypothesis. Immunization against bacteria which do not 

 produce soluble toxins is easily secured by repeated injection of 

 either dead or living bacteria into the organism. It is not easy, how- 

 ever, to confer passive immunity, as in the case of diphtheria, by 

 the injection of the serum of the immunized animal. The im- 

 mune body is alone present in the serum generally and some com- 

 plement must be added to effect bacteriolysis. The serums which 

 aid in the solution of bacteria are known as anti-bacterial ser- 

 ums, which, though not anti-toxic, may check invasions and aid in 

 recovery by destroying bacteria. It is possible to effect an in cor- 

 pore bacteriolysis in the case of typhoid fever if the immune body 

 and complement are injected in sufficient amounts and proportions. 

 As yet the results are not satisfactory from a clinical standpoint. 



A study of figure 20 will show clearly the exact combinations of 

 various substances engaged in the immunity process. Some of the 

 terms must be defined. 



Antigen, the body bacterium; red blood cell, etc., used for stimu- 

 lating the production of thermostabile anti-bodies, which latter are 

 then the substances formed against antigens; inciting substance- 

 antigen. 



Toxins, ferments, see above. 



Toxophore, the poison-carrying fraction of the antigen. 



Haptophore, the binding fraction of antigen or anti-body. 



Complement, the normal thermolabile anti-body substance in 

 serum. 



Zymophore, toxophore for agglutinins and precipitins. 



Cytophile fraction is that part of anti-body which combines with 

 cell, while complementophile fraction joins with complement. 



Immune body, the thermostabile anti-body against bacterial or 

 other cells. 



By immunizing with complement or antibody we obtain respect- 

 ively anti-complement and anti-immune body which experimentally 

 will neutralize the action of these two substances. The comple- 



