284 BACTERIOLOGY 



cell secretions, the "receptors" and their functions are com- 

 paratively simple — i. e., the single haptophore of the simple 

 receptor pairs with that of the intoxicant and a physiologi- 

 cally inert complex results. He conceives antitoxins to be 

 simple receptors of this type, and believes the neutralization 

 of toxins by them to take place in this manner. On the 

 other hand, if the immunization of an animal is accompanied 

 by an acquired power on the part of its serum to disintegrate 

 bacteria, to dissolve alien erythrocytes, to digest such cel- 

 lular elements as epithelium and spermatozoa, to precipitate 

 milk, or agglutinate bacterial or blood-cells, as the studies 

 of Pfeiffer, Bordet, von Dungern, Moxter, Fish, Belfonte 

 and Carbon, MetchnikofP, Gruber, Durham, Widal, and 

 others have demonstrated, then the process becomes less 

 simple, and the atomic grouping of the receptive molecule 

 is correspondingly more complex. In some cases the recep- 

 tor is provided with both a haptophore and a ferment-like 

 (zymophore) group; the function of the former being to 

 combine with and hold in close proximity to the latter the 

 albumin molecule that is to be destroyed or assimilated; in 

 this way bringing and holding the albumin molecule directly 

 under the influence of the zymophore group. In other cases 

 the "receptor" functions symbolically, so to speak, with 

 a complementary something that circulates normally in the 

 blood, the so-called "complement" of Ehrlich and Mor- 

 genroth. Under these circumstances the "receptor" is 

 conceived to be provided with two "haptophore" groups, 

 and becomes an "amboceptor," therefore, the one hapto- 

 phore of which takes up and fixes the invading bacteria 

 tissue-cell, or albumin molecule, while the other pairs with 

 the corresponding haptophore of the complement, fixing 

 the latter in close proximity to the invading body, and 



