Kosearchcs on the Dischartre of tho Electric Orran. 



61 



period, nieasfured iroin the second stiuiulus, beluDgiiig to two 

 subminimal stimuli may take a value smaller than the normal or 

 not is a question which appeared on Oscillograms No. 50 and 51, 

 and wortli wliile investigating hereafter. 



Next we sliall give an example of summation of two dis- 

 charges in response to a closing and an opening-stimulus (Plate 

 XXIL, Oscillogram No. 70). Stimuli of the same type as those 

 used in tlie direct stimulation were given to a nerve-trunk with a 

 proper shunt, by whicli tlie stimulation current through the nerve 

 remains submaximal and yet the current flowing through the 

 oscillograph was sufficiently large to ti-ace its form. The experi- 

 ment was made for another purpose /. e. for the comparison of 

 the intensity of the stimulating current and the magnitude of the 

 resulting discharge. At flrst the stimulating current was increased 

 step by step for five successive experiments. Then the duration 

 of the stimulation current was changed, and commencing with the 

 smaller current, it was increased step by step in the five succeeding 

 experiments in an exactly similar way. In the latter half, the 

 forms of stimuli were not good, and we have not therefore used 

 them in the analysis. The following tal:)le shows the numbers 

 measured on the oscillourram. 



Table XXV. 



Since the duration of the stimulating current did not exceed 

 21x10""^ sec, it must l)e allowed that the opening-stimulus 

 had occurred before tlie end of the refractory period due to the 



