EXPERIMENTS IN STIMULATION. 49 



strip, one beliind the other; but if the shocks are 

 thrown in at a still faster rate, so as to diminish the 

 distance between any two successive waves, a point 

 soon arrives at which every wave mounts upon its 

 predecessor ; and if several waves be thus made to 

 coalesce, the whole strip becomes thrown into a 

 state of persistent contraction. 



In this way sustained tetanus, or single con- 

 traction waves, or any intermediate phase, may be 

 instantly produced at pleasure. In such experi- 

 ments, moreover, it is interesting to observe that, no 

 matter how long the strip be, whatever disturbances 

 are set up at one end are faithfully transmitted to 

 the other. For instance, if an Aurelia be cut into 

 the longest possible strip with a remnant of the disk 

 leff attached at one end, as represented in Fig. 11 

 (p. 70), then all the peculiar time relations between 

 successive contractions which are intentionally 

 caused by the experimenter at one end of the strip, 

 are afterwards accurately reproduced at the other 

 end of the strip by the remainder of the disk. 

 Now, as this fact is observable however complex 

 these time relations may be, and however rapidly 

 the successive stimuli are thrown in, I think it is 

 a point of some interest that these complicated 

 relations among rapidly succeeding stimuli do not 

 become blended during their passage along the 

 thirty or forty inches of contractile tissue. The 

 fact, of course, shows that the rate of transmission 

 is so identical in the case of all the stimuli 

 originated, that the sum of the effects of any series 

 of stimuli is delivered at the distal end of the strip, 



