EXPERIMENTS IN STIMULATION. 49 
strip, one behind 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 
left 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, 
