THE PROTECTIVE SUBSTANCES OF THE BLOOD. 389 



Of these especially the substances of the amboceptor type are in 

 most intimate relationship to the processes of natural immunity, for 

 it is they which, in conjunction with the complement, effect the de- 

 struction of the injurious bacteria. Hence if there is a loss of natural 

 immunity, it will next be necessary to inquire whether there is a lack 

 of complement or of amboceptor. 



I am convinced that these haptin studies open up a new and 

 important field of biological investigation and will add to our knowl- 

 edge concerning the process of assimilation. Clinically they should 

 be of even greater importance. Since I am not in the position to 

 make such chemical investigations on an abundance of material, I 

 have thought it my duty to clearly define my point of view, thus 

 furnishing to others the basis for a proper study of this subject. The 

 significance of this method for pathology and therapy will not perhaps 

 be fully realized until after the lapse of years. 



