190 



The investigation is not altogether consistently carried out 

 but proves with sufficient clearness that I 32, and I 34 are 

 to be looked upon as identical, while the other 4 strains are 

 different from them and from 1 one another. As a control of 

 the suitability of the absorption technique employed it will 

 be noticed that the agglutinations according to the scheme 

 S x , "Y -'- ^ are negative in all cases without regard to whether 

 X and Y are the same or different. This control is not regu- 

 larly included in these and the remaining absorption experi- 

 ments, but so many tests have been made that it can be taken 

 for granted that a strain in all probability will absorb its 

 „homologous" agglutinin with the technique employed. 



One exception however was observed when Pa 5 (28. VIII. 20) 

 only absorbed its homologous agglutinin very slowly. At an earlier 

 date however (I. XII. 19) its absorptive power was normal, as 

 even in a concentration of 1 it practically completely absorbed the 

 agglutinin from serum in a concentration of 1:20. 



