Researches on the Discharj^-o of the Electric Organ. 69 



ing-stiiiiulus was greater than the iiorinaL In tlie.-e experiments 

 tlie direction of the stimnlating current was generally descending 

 on closing the primary circuit, ])ut in the above case the stimulat- 

 ing current was ascending. If tlie above phenomenon may be 

 explained by Pflüger' s contraction law in tlie muscle-nerve prepara- 

 tion, it must l)e recognized that tlie value of the maximal stimulus 

 with respect" to the nerve increases with the progression of the 

 fatigue and hence the same stimulating current will be strong at 

 first, then it will become medial and finally weak with respect to 

 the nerve. If the above explanations l)e correct, here again we 

 liave evidence that the value of the maximal stimulus with respect 

 to the nerve increases with the progression of the fatigue. 



Oscillogram No. <S (Plate XXVI.) shows the case in which 

 the stimulating currents are ascending and descending alternately. 

 This oscillogram shows that the fatigue phenomenon is not tlie 

 consequence of the polarisation at the electrodes. Oscillogram?; 

 No. 78 and No. 78' (Plate XXVI.) show the fatigue by the 

 descending and by the ascending stimuli respecti\'ely. 



Oscillogram No. 1) (Plate XXVII.) is an example of the fatigue 

 phenomenon l)y the direct stimulations. In this case, it is a, 

 remarkable fact that, although the modal latent period is prolonged 

 with the progression of the fatigue, the descending branches of tlie 

 discharge curves coincide with one another into a line. Since the 

 discharges in the two sets of curves have the very same aspect, 

 notwithstanding the stimuli are different in their breadths, the 

 responses must be due to the closing-stimuli only, — the case wlien 

 the closing-stimuli are strong enough to evoke the maximal dis- 

 charges. Therefore the oscillogram shows the fatigue phenome- 

 non in the"case when the stimuli are direct and simple. 



The principal point of this section is that the increase of the 

 magnitude of tlie response at the outset of the fatigue exists in the 

 case of the electric organ as well as in muscle. Therefore the 

 explanation by Fröhlich in tlie case of muscle cannot l)e considered 

 correct. 



