236 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 
one of these open ends, the fluid of course permeates 
the whole tube, and the contraction-wave becomes 
blocked at the transverse line occupied by the tube 
as effectually as if the contractile strip had been cut 
through at that line. 
A glance at Fig 10, again, will show that each 
lithocyst is surrounded by one of these nutrient 
tubes. Upon injecting this tube, therefore, in a 
contractile strip, the effect of the poison may be 
exerted on the lthocyst more specially than it 
could be by any other method of administration. 
In view of recent observations concerning the effects 
of curare on the central nervous masses of higher 
animals, it may be worth while to state that a dis- 
charging lithocyst of Aurelia aurita, when thus 
injected with curare, speedily ceases its discharges. 
This fact alone, however, would not warrant any 
very trustworthy conclusions as to the influence of 
curare upon discharging centres; for it is not im- 
probable that the paralyzing effects may here be 
due to the influence of the poison on the surround- 
ing contractile tissue. 
It is interesting to observe that if the discharging 
lithocyst be injected with chloroform, or a not too 
strong solution of morphia, it recovers in the course 
of anight. With alcohol the first effects of the in- 
jection are considerably to accelerate the frequency 
and to augment the potency of the discharges; but 
the subsequent effects are a gradual diminution in 
the frequency and the vigour of these discharges, 
until eventually total quiescence supervenes. In the 
course of a few hours, however, the torpidity wears 
