INFECTION AND IMMUNITY. 565 



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 

 A^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 presently see, is regarded by Ehrlich as the real 

 antitoxic substance. Assuming a specific combining 

 relation between toxic substances and particular cells or 

 secondary atom-groups of cells — and there are experi- 

 mental grounds for this assumption ^ — it is evident that 

 the combination between the intoxicant and the partic- 

 ular atom-group for which it has a specific af&nity is 

 indirectly the cause of compensatory bioplastic activity 

 on the part of similar surrounding atom-groups that 

 have not been destroyed. This results, as we learned 



' See Wassermann und Takaki : " XJeber tetanus antitoxische Eigen- 

 schaften des normalen Centralnervensystems," Berliner klin. Wochen- 

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

 Hygiene und Infektionskranklieiteu, Bd. xxsvi, g. 299, Madsen ; 

 Ibid., Bd. xxxii. S. 814, 



