(From the Pathological Laboratory of the University of Missouri) 



Fatigue of Excitation and Fatigue of Depression: A 



Comparison of the Reactive Effects of Function and of 



the By-Products of Function on the Nerve Cell. 



by 

 Dayid H. Dolley. 



Synopsis. 



Introduction 35 



Experimental data 36 



The analysis of the experiments on 

 the relation of the fatigue sub- 

 stances to functional activity . 39 

 The distinction on anatomical 

 grounds between functional ac- 

 tivity and functional depression 44 



Fatigue of excitation and fatigue 

 of depression 47 



The relatively greater importance 

 of the effect of excitation than 

 that of depression 50 



The exhaustibility of the nerve cell 52 



Conclusions 58 



Introduction. 

 When one considers the important rôle which toxins and toxic 

 products are known to play in the physiology of the animal organism, 

 it is not surprising that certain phenomena, unexplained or not 

 thoroughly understood, are ascribed to their effect on grounds largely 

 theoretical. Of nothing is this more true than of the anatomical 

 changes which are associated with the functional activity of the 

 nerve cell. Dating from the pioneer work of Hodge (1892), it has 

 become to a greater or less degree recognized that this cell does 

 undergo changes as a result of its functional manifestations. Long- 

 before Hodge's time, workers in another field, of whom Ranke (1868) 



3* 



