15 



In the preceding (16-17) protocols all tubes marked 

 #2 are the serum controls, used to show that the serum 

 itself will not fix complement. Similarly the #o tubes 

 are antigen controls. 



The Bacillus coli antigen, when used with a hemolo- 

 gous antiserum, (table 10) gives complete fixation of 

 complement. The same antigen when used with the ant i- fat 

 serum, (table 11) gives similar results; but when used 

 with the anti-protein serum, (table 12) one fails to 

 obtain a positive reaction. These findings confirm the 

 idea that fats may act as antigens and lend proof to the 

 specificity of the reaction. The protein antigen, when 

 used with its homologous antiserum (table 6) gave results 

 which were nearly completely positive, but it is worthyof 

 note that the reaction was not as clear cut or as satis- 

 factory as the previous tests. When used with the other 

 antisera (tables 7-9) there was no complete fixation. 

 Thus there is evidence that the fats are true specific 

 antigens and that the protein material plays a minor role, 

 if any. 



B. Agglutination tests. Although the presence of 

 agglutinins probably does not indicate protective ability, 

 as Bordet (26) showed that horse serum clumps tetanus 

 bacilli; yet the horse is very susceptible to tetanus, 

 nevertheless, the experimental production of agglutinins 

 in the serum of immunized animals is very indicative of 

 a specific reaction. 



The sera obtained from the immunized animals were 

 tested against the B. coli antigen. Ten drops of serum, 

 in various dilutions, were added to ten drops of antigen. 

 The tubes were well shaken and incubated at 37C. for one 

 hour. The results are recorded as follows: 



Complete 

 agglutination 



Partial 

 agglutination 



No 

 agglutination 



Table #18. B. Coli Antigen with Heraologous Antiserum 



