194 THEORETICAL DEDUCTIONS 



The mechanism of anti- or tachyphylaxis must therefore 

 be considered and explained in two different ways: 



1. As a specific neutralization of the antigen by the excess 

 antibody. 



2. As a reflex reaction of the nervous centers on the intra- 

 cellular metabolism caused by the selective action of certain 

 antigens on the nerve centers regulating cellular nutrition. 

 In this case, the reciprocal specificity of antigens and anti- 

 bodies does not come into play, or plays only a secondary 

 role. 



