8 



IMMUNE SERA 



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

 " 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, 



toxophore group 



, POISON MOLECULE 



FlG. I 



are able to combine with the greatest variety of 

 foreign substances and convert these into nourish- 

 ment suitable to the requirements of the active 

 central body. They are comparable to the pseudo- 

 podia of the lower animals, which engulf food par- 

 ticles and assimilate the same for the immediate 

 use of the organism. In order that any substance 



