98 JELLY-FISH, STAR-FISH, AND SEA-URCHINS, 
In view of this anomaly, I was led to think that 
if the rate of the stimulus-wave is dependent in 
a large degree on the strength of the stimulus that 
starts it, the slow rate of nine inches a second 
might be more than doubled, if, instead of using a 
stimulus so gentle as not to start a contraction- 
wave, I used a stimulus sufficiently strong to do 
this. Accordingly I chose a specimen of Aurelia 
wherein the occurrence of tentacular waves was 
very conspicuous, and found, as I had hoped, that 
every time I stimulated too gently to start a con- 
traction-wave, the tentacular wave travelled only 
at the rate of nine inches a second; whereas, if I 
stimulated with greater intensity, I could always 
observe the tentacular wave coursing an inch or 
two in front of the contraction-wave. 
It is remarkable, however, that in this, as in all 
the other specimens of Aurelia which I experimented 
upon, the reflex response of the manubrium was 
equally long, whatever strength of stimulus I applied 
to the umbrella; or, at any rate, the time was only 
slightly less when a contraction-wave had passed 
than when only a tentacular wave had done so. 
The loss of time, however, appears to take place in 
the manubrium itself, where the rate of response 
is astonishingly slow. ‘Thus, if one lobe be irritated, 
it is usually from four to eight seconds before the 
other lobes respond. But the time required for 
such sympathetic response may be even more 
variable than this—the limits I have observed 
being as great as from three to ten seconds. In all 
cases, however, the response, when it does occur, is 
