2:{n 



Table U. 

 Immunization of Fibroblasts by Dog Serum in 8 Per Cent Concentration of 



Antigen. 



up 2 

 o 

 <o 



9 10 11 12 

 Passage 



13 14 15 16 17 18 19 20 



Fig. 50. 

 Curve showing the degree of immunization of fibroblast through twenty-two 

 passages. Human ascitic fluid was used as antigen in a concentration of 

 7 per cent. The ordinates represent the quotient of the rate of growth of 

 the immunized strain divided by that of the non-immunized strain in a high 

 concentration of antigen, and the abscissae the number of passages. 



In olher expcrimcnls clog scM'iini was used as antigen and 

 similar resiills were obtained. The dog serum was found 

 lo be a good deal more toxic against chicken fibroblasts 

 than the human ascitic fluid. 



All investigation was made as lo the concentration of 

 the antigen used and the degree of immunization of a strain 



