MECHANISM OF ANTIBODY FORMATION 137 



tive manner the conclusion of previous investigators that the various 

 specific antibodies in a species of animal are closely related anti- 

 genically. Thus the only antigenic specificity demonstrable for the 

 antibodies investigated was that due to their common origin, and "the 

 groupings/' as stated by the authors, "responsible for their antibody 

 function, constitute either a small part of the total protein molecule 

 or else are non-antigenic." 



f. A Comment on the Use of Antigen-Antibody Complex for the 

 Production of Anti-Antibodies. According to our present concept the 

 determinant groups in antigenic molecules which specifically stimulate 

 the production of antibodies in vivo are identical with the groups which 

 combine with the antibodies produced. It would therefore be expected 

 when these groups of antigens are saturated with antibodies the 

 treated antigens would be deprived of their capacity to develop specific 

 antibodies. Olitzki (1935) reasoning in this manner reviewed the 

 previous studies concerning this question and found it controversial. 

 He then set out to clarify this controversy. 



He reported that the immunization of rabbits with E. ty-phosa sensi- 

 tized with anti-serum to 0-antigen did not reduce the production of 

 H-agglutinin, but reduced the production of 0-agglutinin to nearly 

 20 per cent of the normal immunization effect by an unsensitized 

 vaccine. Sensitization of the vaccine by H-serum reduced only the 

 production of H-agglutinin to 20 per cent of the normal immunization 

 effect. Sensitization of the vaccine by both H- and O- serum reduced 

 the production of both types of agglutinins. Olitzki found that the 

 injection of sensitized antigen together with larger amounts of free 

 antibody (immune serum) suppressed the formation of agglutinins 

 completely. The effect was the same whether the excess serum was 

 administered before or after the inoculation of the sensitized vaccine. 



Phage lyzed bacteria produced at least the same quantities of anti- 

 bodies as whole bacteria. But after sensitization with the same quantity 

 of immune serum, phage lyzed bacteria were completely deprived of 

 their ability to produce antibodies, while the phage untreated bacteria 

 remained effective. 



It is interesting to note in the results of OHtzki that after injection 

 of the same quantity of free immune-agglutinins as used for sensitiza- 

 tion the free agglutinins could be recovered in the serum. Especially 

 the H-agglutinins were demonstrable in the serum on the next day 



