ACCUSTOMANCE AND VITAL INERTIA 167 



for accustomance and counteraction to be adequately developed. 

 The existence of this law was first recognized by Weigert ; 1 

 it may be said to form the basis of Ehrlich's side-chain theory 

 of immunity. 



1 C. Weigert, Gesammelte Abhandl Leipzig, 1906, 1. 



