64 Art. 1.— K. Fuji: 



of a dynamo, and the nerve-trunk attached to the organ was 

 stimulated by the induced current. For this and the other ends, 

 our shutter was so constructed that, wlien we made proper connec- 

 tions, the stimulating current could flow only when the shuttei' 

 opened (P^ate IV., c). The number of the momentary stimuli 

 given amounts to 885 per sec. In this case the stimuli varied a 

 little .in their strength, and hence another experiment No. 85 

 was made in which the induction coil was not used. Here, 

 as stimulus, a current from eight accumulators was interrupted 

 by the same contrivance as No. 07, no induction coil being 

 used. The stimuli were regular, and tlieir number amounted to 

 1412 per sec. As may be seen in the oscillograms, tlie dis- 

 charges were not so regular as to account for one determinate 

 l)eriod, being a series of high and Ioav superposed discharges. This 

 nn'ght be the case because the stimuli were not maximal, though 

 in the beginning part it seems to be so. From many other experi- 

 ments it seems to me, that tlie liminal value of the stimulus for the 

 maximal response in tlie nerve increases with the temporary 

 fatigue, and by this assumption the irregularity of the discharges 

 may be easil}^ interpreted. Hence assuming that the stimuli were 

 sufficiently strong at the beginning, we may take as the period of 

 response, the inter\^al between the first and the second discharge, 

 and we get as its value ]17x]0~*sec. in No. S6, the temperature 

 of the organ being 15°C. For the more advanced discussion the 

 more precise analysis should l)e necessary, and hence we here 

 allude to this as a mere experimental result. 



The summary of this section is : — 



i.) A\'hen two successive stimuli separated l»y an interval a 

 little greater than the refractory period are given at a point in a 

 nerve of the electric organ, the modal latent period of the second 

 discharge is prolonged with regard to the normal. 



ii. ) The recovery of this prolongation follows an exponential 

 law with respect to the intei'val between the two stimuli. 



iii.) The prolongation of the modal latent period of the 

 second discharge is accompanied by the variation of the maximum 

 electromotive force of the second discharge. 



