THE BARBED THREADS. 143 



capsules as weapons of offence has occurred to me. I 

 was examining the brilliant purple filaments oi 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 

 thea(juatio boxwhich I was using there was, still affixed 

 to one of the glasses, the sucker of a Gibbous Starlet 

 ( Asterina gibhosa) that I had just before been looking 

 at. The cihary 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 



