THE DEFENSES OF THE BODY 297 



is confined to the cells or integers of cells that it destroys, 

 but occurs rather indirectly as a function of the surround- 

 ing uninjured tissues that have been excited to bioplastic 

 activity through the removal of the restraint hitherto 

 exerted by the cells destroyed by the irritant; and, finally, 

 when such bioplastic activity is called into play there is 

 always fo/percompensation i. e., there is more plastic 

 material generated than is necessary to compensate for the 

 loss. Ehrlich applies this idea to the individual cell, which 

 he conceives to be a complex molecule, comprising a primary 

 central nucleus to which are attached by side chains its 

 secondary atom-groups, in much the same way that our 

 conception of the reaction structure of complex organic 

 chemical compounds is represented graphically. Injury to 

 one or more of these physiologically essential atom-groups 

 results, according to the view of Weigert, in disturbance 

 of the cell-equilibrium and consequent effort on the part 

 of the surrounding atom-groups at compensatory repair. 

 With this liberation of bioplastic energy there is more 

 plastic material generated than is necessary for the repair 

 of the injury. The excess of this material finds its way into the 

 blood and, as we shall see presently, is regarded by Ehrlich 

 as the real antidotal, immune, or protective substance. 



Assuming a specific combining relation between toxic sub- 

 stances and particular cells or secondary atom-groups of 

 cells and there are experimental grounds for this assump- 

 tion 1 it is evident that the combination between the intoxi- 

 cant and the particular atom-group for which it has a specific 



1 See Wassermann und Takaki, Ueber tetanus antitoxische Eigen- 

 schaften des normalen Centralnervensystems, Berliner klin. Wochen- 

 schrift, 1898, No. 1, S. 5. Neisser und Wechsberg, Zeitschrift fur Hygiene 

 und Infektionskrankheiten, Bd. xxxvi, S. 299. Madsen, ibid., Bd. xxxii, S. 

 214. 



