ACTINIA AND OTHER ACTINOID POLYPS. ao 
animal so touched, torpor and speedy death. Since the discoy- 
ery of these cnid@ (lasso-cells) the fatal power has been sup- 
posed to be lodged in them. Baker, a century ago, in speak- 
ing of the Hydra, suggested that “there must be something 
eminently poisonous in its grasp ;” and this suspicion received 
confirmation from the circumstance that the Hntomostraca 
which are enveloped in a shelly covering frequently escape un- 
hurt after having been seized. The stinging power possessed 
by many Meduse, which is sufficiently intense to be formida- 
able even to man, has been reasonably attributed to the same 
organs, which the microscope shows to be accumulated by mil- 
lions in their tissues. 
“Though I cannot reduce this presumption to actual cer- 
tainty, I have made some experiments, which leave no reason- 
able doubt on the subject. First—I have proved that the ecthor- 
eum (tubular thread of the lasso-cell) when shot out, has the 
power of penetrating, and does actually penetrate, the tissues 
of even higher animals. Several years ago, I was examining 
one of the purple acontia of Adamsia palliata ; no pressure 
had been used, but a considerable number of cnidw had been 
spontaneously dislodged. It happened that I had just before 
been looking at the-sucker-foot of an Asterina, which remained 
still attached to the glass of the aquatic box, by means of its 
terminal disk. ‘The cilia of the acontéwm had, in their rowing 
action, brought it into contact with the sucker, round which it 
then continued slowly to revolve. The result I presently dis- 
covered to be, that a considerable number of the cnidw@ had 
shot their ecthorea into the flesh of the sucking disk of the 
Echinoderm, and were seen sticking all round its edge, the 
wires (lassos) being embedded in its substance even up to the 
very capsules, like so many pins stuck around a toilet pin- 
cushion. 
