90 BIOCHEMICAL SYSTEMATICS 



may be expected to become increasingly significant. Modifications of 

 the strictly quantitative precipitin tests, even with increased sensi- 

 tivity, seem to possess some inherent limitations. As a general criticism 

 it appears that proponents of the precipitin methods have expended 

 tremendous effort in the development of techniques without exerting 

 equivalent efforts to set up critical "test" experiments or to pursue the 

 theoretical aspects of antibody-antigen reactions at the biochemical 

 level. 



