576 COLLECTED STUDIES IN IMMUNITY. 



failed utterly; his experiments, on the contrary, are to be welcomed 

 as supplementing the arguments supporting the amboceptor theory. 1 



1 The mistake contained in our previous conception of antiamboceptors, 

 that they were antibodies directed against the cytophile group, is essentially 

 one regarding the situation of the point of attack. In this connection we may 

 look upon certain chemical substitutions as furnishing ready comparison; for 

 example, the different substances resulting when the benzole nucleus is substi- 

 tuted in the ortho, meta, or para positions. Considering how difficult these 

 problems are, it is not surprising that a statement concerning localization will 

 now and then be made which subsequent deeper study shows must be corrected. 

 Even so high an authority as Kekule once erred in defining a compound, and 

 yet this did not in the least affect his fruitful hypothesis. In our case after the 

 way ha,d been cleared by the demonstration of the "blocking of complements" 

 (the nature of which corresponds to an antiamboceptor action), and by the 

 studies of Pfeiffer and Friedberger, it was an easy matter to arrive at a correct 

 interpretation and transfer the site of the antiambocepter's action to the comple- 

 mentophile group. It is at once clear that this merely fulfills an old postulate 

 of the side-chain theory. It would therefore be interesting to see how Bordet 

 could explain the facts according to his sensitization theory, and to have him 

 show how the sensitizers, which he believes do not combine with the comple- 

 ment, excite the production of substances whose constitution is just what would 

 be demanded of immunization products of " complementophile groups." 



