EXPERIMENTS IN STIMULATION, 57 
answer the first of these questions, therefore, I built 
up a staircase in the ordinary way, and then sud- 
denly transferred the electrodes to the opposite side 
of the umbrella from that on which they rested while 
constructing the staircase. On now throwing in 
another shock at this part of the contractile tissue 
so remote from the part previously stimulated, the 
response waS a maximum response. Similarly, if 
the electrodes were transferred in the way just 
described, not after the maximum effect had been 
attained, but at any point during the process of 
constructing a staircase, the response given to the 
next shock was of an intensity to make it rank as 
the next step in the staircase. Hence, shifting the 
position of the electrodes in no wise modifies the 
peculiar effect we are considering; and this fact 
conclusively proves that the effect is a general one, 
pervading the whole mass of the contractile tissue, 
and not confined to the locality which is the imme- 
diate seat of stimulation. Nevertheless, this fact does 
not tend to prove that the staircase effect depends 
on the process of contraction as distinguished from 
the process of stimulation, because the wave of the 
former process must always precede that of the 
latter. But, on the other hand, in this connection 
it is of the first importance to remember the fact 
already stated, viz. that a current which at the be- 
ginning of a series of stimulations is of slightly less 
than minimal intensity presently becomes minimal, 
and eventually of much more than minimal in- 
tensity—a staircase being thus built up of which 
the first observable step (or contraction) only occurs 
