228 JELLY-FISH, STAR-FISH, AND SEA-URCHINS, 
being thus no longer responsive to central stimula- 
tion. It remains, however, for a long time responsive 
to stimulation of the neuro-muscular sheet ; indeed, 
the strength of the alcohol solution must be very 
considerable before loss of muscular irritability 
supervenes. It may thus be made to do so, how- 
ever; and on then transferring the animal to normal 
water, recovery begins in from three minutes to a 
quarter of an hour. The first contractions are very 
feeble, with long intervals of repose; but gradually 
the animal returns to its normal state. 
The above remarks apply also to Tiaropsis. In 
Tiaropsis indicans the manubrium recovers in normal 
water sooner than the nectocalyx. Both in Sarsia and 
Tiaropsis the manubrium and tentacles are retracted 
while exposed to alcohol, and, after transference to 
normal sea-water, the animals float on the surface, 
presumably in consequence of their having imbibed 
some of the spirit. The period during which flota- 
tion lasts depends, (a) on the strength of the alcohol 
solution used, and (b) on the time of exposure to its 
influence. It may last for an hour or more; but in 
no case is recovery complete till some time after the 
flotation ceases. 
11. Curare—Curare had already been tried upon 
Medusz, and was stated to have produced no effects ; 
it is therefore especially desirable that I should 
first of all describe the method of exhibiting it 
which I employed. 
Having placed the medusa to be examined in a 
fiat-shaped beaker, I filled the latter to overflowing 
with sea-water. I next placed the beaker in a 
