Kesearclies on the Discharge of the Electric Organ. 7]^ 



The modal latent periods could not be measured, for the- 

 summits of the curves were on tlie outside of the film. Therefore 

 the time between the stimulus ai^d the beginning of the discharge 

 was measured. 



In Plate X. a grai)h representing the time between the stimulus; 

 and the l)eginning ()f tlie discharge with regard to the position of the 

 electrodes is drawn. In this figure we see tliat the clieck point 

 lies very closely on the curve. Tliis shows that the experi- 

 ment was not affected by any progressive change. Tlie points 2,3, ■ 

 4, 5 and arrange themselves on a straight line, while the point 1 

 falls on tlie upward side of the line. This sliows that Ijetween the 

 points 2 and (3 in the nerve, tlie speed of propagation was uniform 

 Avhetlier tlie point concerned was near to or far from the stimulated 

 point. As the value of the speed, we (obtained Toi metres per 

 sec, the temperature of the nerv(3 l)eiiig 11 (> °C. The discrepancy 

 of the point Xo. 1 must have its cause in the alteration or decay of 

 the nerve at that portion which occurred near the excised end of 

 the nerve. This becomes very olnious when we examine the 

 oscillogram, for tliere we see that the discharge curve coriespond- 

 ing to Xo. 1 is very low compared with the other discharges, while 

 the stimulus is ii()t smaller than the others. The prolongation of 

 the latent period of the discharge evoked by a stimulus given at a 

 point near the excised end of the nerve, may be explained by one 

 of tlie following as-uinptions. (1) The sjieed of pro})agatioii in the 

 portion near the excised end of the nerve altered l)y its injury 

 is smaller tli.an the normal. (2) The local latent ])eriod at the 

 nerve-ending or in the organ, I.e. the interval between the instant, 

 at which the disturbance arrived at the nerve-ending, and that of 

 the beginning of the discharge is greater when the disturbance in 

 the nerve is smaller. (.'>) The speed of ]^roi)agation of the nerve 

 excitations differing in magnitude has different values, the stronger 

 the larger. (4) The local latent period at the point of stimulation 

 is greater when that portion of the nerve is altered. The cases 

 (2) and (8) cannot be considered to be true from the standpoint of 



