INTERFERENCE OF EXCITATIONS 201 



food. But here the increase in the processes of assimilation never 

 occurs momentarily, and indeed this increase is so extremely 

 slight that it can only be demonstrated over a long course of time. 

 These totally negative results of my investigation had awakened 

 strong doubts concerning the assimilation hypothesis of inhibition. 

 Above all, this explanation seemed to me to be impossible for the 

 nervous system. I searched, therefore, for another explanation 

 for the processes of inhibition in the nervous system. If the 

 increase of energy production resulting from the application of 

 a stimulus is dependent upon an excitation of a dissimilative 

 nature, then one is justified to look upon the reduction of func- 

 tional energy production as an expression of an antagonistic pro- 

 cess to that of dissimilatory excitation. In this respect the 

 Gaskell-Hering hypothesis of inhibition rests upon a firm founda- 

 tion. When, however, this hypothesis assumes an antagonism 

 between dissimilatory and assimilatory excitation, then it must 

 not be overlooked that a second antagonism is possible between 

 dissimilatory excitation and dissimilatory depression. The antag- 

 onism need not involve the two types of metabolism, it may 

 depend upon variations of one type. When, therefore, the hy- 

 pothesis that inhibition is brought about by assimilatory excita- 

 tion meets with insuperable difficulties, the possibility should be 

 considered if it is not more likely dependent upon dissimilatory 

 depression. These reflections induced me to investigate if con- 

 ditions could not be produced experimentally wherein dissimi- 

 latory depression could bring about inhibitory processes in the 

 nervous system. The most essential requirement was, that dis- 

 similatory depression should quickly develop and pass away with 

 like rapidity, for inhibition of the nervous system sets in momen- 

 tarily and disappears again momentarily. Another important 

 requisite is, that both interference stimuli are individually capable 

 of producing dissimilatory excitation, for the inhibitory processes 

 of the nervous type may be assumed to be the result of dissimi- 

 latory excitation which produce by their interference inhibition, 

 for the nerve fibers, as already stated, are capable of conducting 

 only dissimilatory excitation to the responding organ. As I 

 studied the problem in this manner, it became clear to me that all 



