380 COLLECTED STUDIES IX IMMUNITY. 



mental study, Dr. Morgenroth and I have endeavored in these to dis- 

 cover the mode of action of these two components on the susceptible 

 object, the red blood-cells. For this purpose we first prepared solu- 

 tions containing either only the immune body, or only the complement. 

 These solutions were then brought into contact with the appropriate 

 blood-cells, after which the fluid and blood-cells were separated by 

 means of the centrifuge. The two portions were then tested to 

 determine whether these substances had been taken up by the blood- 

 cells. These experiments showed that the blood-cells are incapable 

 of taking up complement alone, whereas they eagerly take up the 

 immune body. If, however, the serum contains both components 

 they are both bound by the blood-cells in question. 



A confirmation of this fact was furnished by Bordet, who showed 

 that blood-cells or bacteria which by previous treatment have become 

 loaded with immune body, abstract the complement from fluids con- 

 taining the same with great avidity. These facts have been confirmed 

 from all sides. They show that the blood-cells, or the bacteria, anchor 

 the immune body but not the complement, but that the complement 

 is also bound as soon as the immune body has been anchored. 



Morgenroth and I have made these relations more easily com- 

 prehensible by means of the following assumptions concerning the 

 constitution of the immune body and complement. 



We believe it necessary to assume that the immune body possesses 

 two kinds of haptophore groups, one of high affinity which combines 

 with a corresponding receptor group of the red blood-cell or bacterium; 

 the other a group of less affinity which combines with the complement 

 exerting the deleterious action on the cell. Hence the immune body 

 is a kind of intermediate element which links complement and red 

 blood -cells. In order to denote this function I have proposed the 

 name " amboceptor, " which is to express this two-sided grasping 

 power. 



According to our conception the complement possesses a con- 

 stitution analogous to that of the toxins. Thus it possesses a hapto- 

 phore group which effects the specific combination with the ambo- 

 ceptor. The presence of this is confirmed by the existence of analogues 

 of antitoxins, namely, corresponding anticomplements. Besides this 

 the complement possesses a second group, the cause of the injurious 

 action, which is analogous to the toxophore group of the toxins. 

 In view of the properties of this group, partly toxic, partly ferment- 

 like, I have decided to name it the "zymotoxic" group. If one cares 



