90 COLLECTED STUDIES IX IMMUNITY. 



very interesting to see these as yet purely theoretical suggestions 

 of Durham proved by means of experiments. 



The pluralistic standpoint adopted by us creates numerous 

 difficulties for thorough analytical work in this field, but it leads to a 

 deeper insight into the complicated problems and may perhaps 

 also prove of value in the practical applications in immunity. 



I. Observations on the Pluralistic Conception of the Cellular 



Immunity Reaction. 



To begin, we shall briefly sketch one of the points of view yielded 

 by the plurimistic conception, which seems to be of some practical 

 value. Let us assume that a cell, e.g., a bacterial cell, possesses 

 twenty different groups ; then twenty different antibodies correspond- 

 ing to these will be possible. Each haptophore group of the bacterial 

 cell will then represent an isolated point of attack for one particular 

 immune body. It is certainly most logical to conclude that the 

 possibility of successfully combating a certain bacterial infection 

 increases directly with the number of kinds of immune bodies which 

 act on the bacterial cell. 1 The ideal effect would obviously be attained 

 if it were possible to produce a serum so constituted as to contain 

 immune bodies for all the groups present in the bacterial cell. 



The phenomenon of antibody formation as it proceeds according 

 to the side-chain theory is a very complex one, and is composed 

 of a number of phases (binding, super-regeneration, thrusting-off) 

 which are partly independent of each other. Hence a variety of 

 circumstances may arise which exert an inhibitory action at certain 

 points. 



To begin, the cell may be so severely damaged by the anchoring 

 of certain poisonous substances that the formation of antibody 

 does not occur at all, or occurs in only a very slight degree; for this 

 antibody production, which is a kind of regeneration process, pre- 

 supposes a certain degree of cell efficiency. 2 



This damaging effect will result especially with highly toxic sub- 



1 It is, in fact, conceivable that the occupation of a single group only produces 

 a certain amount of injury to the cell without being able to cause its death. The 

 danger to the life of the bacterial cells would increase in proportion to the number 

 of partial injuries, which again would correspond to the increase in the number 

 of types of receptors. It is possible that the potent bactericidal sera so far 

 obtained owe their success to a certain plurality of the immune bodies. 



2 Weigert has already called attention to this. See Lubarsch-Ostertag, 

 Ergebnisse der Pathologic, 1897, page 138. 



