Page:The aquarium - an unveiling of the wonders of the deep sea.djvu/184

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THE BARBED THREADS.
143

capsules as weapons of offence has occurred to me. I was examining the brilliant purple filaments of Adamsia palliata, under a power of 200 diameters. There was no pressure applied, but a considerable number of the small capsules were spontaneously dislodged. In the aquatic box which I was using there was, still affixed to one of the glasses, the sucker of a Gibbous Starlet (Asterina gibbosa) that I had just before been looking at. The ciliary action of the Adamsia's filament had been wheeling it round and round, partly in contact with the sucker, and the result was that a good number, (a dozen or two at least) of the thread-capsules had shot their darts into the sucker, and were seen sticking all around its edge, their threads imbedded into its substance, even up to the very capsules. I thus saw how readily these barbed threads are projected into the flesh of any offending animal; and if they are accompanied, as is probable, by a subtle poisonous fluid, they are doubtless very effective.

The filament under pressure shows thread-capsules in innumerable millions, forming the greatest part of its substance. This immense number is probably intended to meet the continual demand for the use of the weapons during the life of the animal; since, once shot, the thread sticks in the wounded flesh, and carries the capsule with it; while, if it fail to strike I suppose it can never be recoiled, and re-inclosed.

The filaments, which are of the same rose-purple hue as the spots, are excessively abundant in this species, and are projected on the slightest disturbance of the animal. The firmness with which they adhere to the fingers when accidentally touched, so that it is