ALAN ARTHUR BOYDEX. 



homologous reaction is given as 100 per cent, and the heterologous 

 reactions in per cent, of the homologous titer for each antiserum 

 and antigen. The results are given in Tables VI II. to XIII. 

 A part of these results are given in graphical form in Figs. 2 



$00 



100 



All A tit.- 



17 1J 



All. Anti-Pi l(ratt-it) 



II 11 li 



t7 



FIG. 2. Comparison of two different anti-pig sera from rabbits. These antisera 



were of the same homologous titer. 



to 8. In these figures the ordinates represent antigen dilution, 

 or titer, given in the geometric progression of the increasing 

 dilutions employed. The homologous reaction is given first in 

 order from left to right along the abscissa and then follow 

 heterologous reactions in the order of relationship to the homolo- 

 gous protein. 



Table VIII. gives the reactions of three different antipig sera, 



' which were obtained from rabbits and one from a fowl. 



id ('4 were injected with the blood of the same pig, A23 



M""<1 of another pig. These three antisera were of 



