ANTITOXINS 17 



poisons. The toxophore group is a very delicate 

 one and much more readily decomposed than the 

 combining (haptophore) group. Ehrlich reasoned 

 that in order for a poison to be toxic to an organ- 

 ism, i.e., in order that the toxophore group be able 

 to act destructively on a cell, it is necessary for the 

 haptophore group of the poison to combine with 



toxophore group 



, POISON MOLECULE 



FIG. 



the cell. " In every living cell," Ehrlich said, 

 " there must exist a dominating body [Leistungs 

 Kern] and a number of other chemical groups or 

 side chains. These groups have the greatest variety 

 of function, but especially those of nutrition and 

 assimilation." 



The side chains, then, according to this author, 



