Fatigue of Excitation and Fatigue of Depression etc. 53 



have already begun to show up in popular writings. To begin with, 

 as it has * already been expressed, this idea amounts not only to 

 making the nerve cell a law to itself, an exception to the other- 

 wise universal working of fundamental cellular principles, but in- 

 deed it would come very close to ascribing to this cell an im- 

 mortality only limited by the mortality of other types with which it 

 is associated in the same organism or by the attack of disease against 

 itself. While isolated citations are recognized as prone to be unfair, 

 I shall venture the following to show the neglect of organic fatigue. 



Thus Woodworth (1901) says: "(We) may legitimately doubt that 

 ordinary or even rather unusual amounts of work ever produce in 

 the normal nervous system any actual exhaustion or paralysis of any 

 groups of cells." In discussing the possible objections, he grants the 

 histological work, says that the changes represent wear and tear, but 

 thinks that they are due to an extreme degree of fatigue and do not 

 indicate functional paralysis. The lesions of the chromatic substance 

 are considered to be due merely to a consumption of reserve energy 

 and not to affect the integral part of the cell, for, after the substance 

 is used up, "the blood may still provide enough energy for a good 

 degree of activity". For Woodworth, fatigue is a matter of sensation, 

 a warning, but not organic, because if we disregard it, we can go 

 on afterward as well as before. 



A statement from Hough (1901) shows the usual place ascribed 

 to the waste products: "The one indisputable cause of ordinary fatigue 

 thus far established is the presence of the waste products of activity." 



Sherrington's (1904) well-known theory that the site of fatigue 

 is located at the synapse needs no statement. For the comon efferent 

 path, involved for example in the scratch reflex, it is sufficient to say 

 that he only declares it "relatively unfatlgable". 



Joteyko's (1904) oft-quoted experiments have probably furnished 

 the chief basis for wider deductions in regard to the non-fatigability 

 of the nervous centres. That they prove a relative non-fatigability 

 is not questioned. As will appear in a moment, the writer thinks 

 also "qu'on peut admettre le principe de la grande résistance à la 

 fatigue des centres nerveux médullaires". But Joteyko's biased new- 



