227 



lo be an accidenlal error, and llu- jjlicnoinciioii ina\- l)o 

 related lo some kind ol" anaphylactic process. I-iirtlu-r ex- 

 periments ol" this kind may probably throw some li.^hl 

 upon llie mystei'ia of anaphylaxis and anyway lead lo in- 

 teresting observalions. 



12 3 4 5 6 7 



6 9 10 11 12 13 14 15 16 17 18 19 20 

 Passage 



Fig. 48. 

 The rate of growth of the immunized strain and subcultures. The dotted 

 line represents the rate of growth of fibroblasts in the culture medium 

 containing 7 per cent ascitic fluid. The solid lines (A, B, C, D and E) 

 represent the rate of growth of the subcultures of the immunized strain in 

 a medium containing 50 per cent ascitic fluid. 



The rale of growth of Ihe immunized strain in the high 

 concentration of antigen, divided by the rale of growth of 

 the non-immunized strain in the high concentration, ex- 

 presses the degree of immunization or resistance lo the 

 toxic action of the foreign protein. Fig. 49 is a curve whicli 

 indicates the degree of immunization at given periods during 

 the long experiment of the 17 passages. The curve rises 



15* 



