MECHANISM OF THE ACTION OF ANTIAMBOCEPTORS. 563 



no sensitizers whatever for the species of cell in question can 

 yet excite the production of antibodies directed against them. 

 The matter takes on an entirely different aspect if we regard this 

 phenomenon from the standpoint of the amboceptor theory. Ac- 

 cording to what has been said above we at once see that two func- 

 tionally different types of antiamboceptors are possible. In Bordet's 

 case the normal rabbit serum possessed no amboceptors (i.e., no cyto- 

 phile groups) for ox blood; therefore the antibodies which are de- 

 veloped cannot be antiamboceptors directed against the cytophile 

 groups. Hence by exclusion one will already pronounce them anti- 

 ambocepturs of the complementophile group. The facts brought for- 

 ward by Bordet all go to confirm this. 



If such antiamboceptors are to be produced, the only requisite 

 is that the serum used for immunization must contain the corre- 

 sponding complementophile groups. Is this the case in normal 

 rabbit serum? Every normal rabbit serum, as Bordet admits, con- 

 tains a large number of different amboceptors. If, by immunizing 

 with a given species of cell, a new specific amboceptor develops in 

 the serum, the new element in the receptor apparatus is really only the 

 cytophile group, which is produced in response to immunization. The 

 complementophile apparatus need not suffer the least change quali- 

 tatively; in fact according to our conception it usually does not 

 change markedly, there is merely an increase in the complemento- 

 phile groups corresponding to the formation of the additional immune 

 body. We have already expressed this opinion in a previous paper. 1 

 "In my judgment we shall arrive at a correct conception if we pro- 

 ceed from the standpoint that in general the specific amboceptors 

 exhibit a uniform structure so far as their complementophile portion 

 is concerned, while their cytophile groups, which physiologically 

 are concerned with the absorption of food, differ most widely." 



It must not be thought that this uniform constitution of the com- 

 plementophile portion 2 contradicts the assumption of a multiplicity 



1 P. Ehrlich, Betrachtungen iiber den Mechanismus der Amboceptorwirkung 

 und seine teleologische Bedeutung. Koch Festschrift, Jena, 1903. 



2 For the present we cannot say whether the complementophile complex 

 is really uniform throughout or whether, perhaps, certain partial groups do 

 not differ in the individual amboceptor types of the same animal species. Such 

 a condition is easily conceivable. In any event we must assume that the com- 

 plementophile apparatus of the amboceptors of a given species is identical 

 at least in some essential part of its haptophore functions, and that this char- 

 acterizes it as coming from the animal species in question. 



