THEORIES OF IMMUNITY. 



marked bactericidal action upon the anthrax 

 bacillus, whilst the animal itself succumbs very 

 promptly to an infection by these bacilli, is an 

 illustration in point, and is not by any means the 

 only one that can be brought forward. 



Whether or not this bacteriolytic action is the 

 same as that seen after the condition of immu- 

 nity has been produced has not been shown; if 

 it is the same, its production must be accounted 

 for, and the reactions may be explained in the 

 same way as has been adopted for the illustra- 

 tion of the other parts of Ehrlich's theory; if, 

 however, it is not the same, and its presence 

 seems to show that a bactericidal property of 

 the serum does not of necessity indicate a con- 

 dition of immunity, then the explanation of its 

 appearance and the method by which it acts has 

 not yet been furnished. 



Somewhat the same position must be taken in 

 regard to the phenomenon of agglutination. 

 The relation of this phenomenon to immunity 

 does not appear to be any more intimate than 

 that of the possession of a bacteriolytic property 

 on the part of the blood serum. Agglutination, 



86 



