374 EVENINGS AT THE MICROSCOPE. 



same time of a highly subtle poison into the wound ; some 

 venomous fluid escaping with the discharge of the ectho- 

 reum, which has the power, at least when augmented by 

 the simultaneous insertion of scores, or hundreds, of the 

 weapons, of suddenly arresting animal vigour and speedily 

 destroying life, even in creatures — fishes, for example — 

 far higher than the Zoophyte in the scale of organisation. 

 I have seen a little fish in perfect health come into acci- 

 dental contact with one of the acontia of an irritated 

 Sagartia, when all the evidences of distress and agony 

 were instantly manifested ; the little creature darted wildly 

 to and fro, turned over, sank upon the bottom, struggled, 

 flurried, and was dead. 



Admitting the existence of a venomous fluid, it is dif- 

 ficult to imagine where it is lodged and how it is injected. 

 The first thought that occurs to one's mind is, that it is 

 the organic fluid which we have seen to fill the cnida, and 

 to be forced through the everting tubular ecthoreum. But 

 if so, it cannot be ejected through the extremity of the 

 ecthoreum, because if this were an open tube, I do not see 

 how the contraction of the fluid in the cnida could force it 

 to evolve ; the fluid would escape through the still inverted 

 tube. It is just possible that the barbs may be tubes open 

 at the tips, and that the poison-fluid may be ejected 

 through these. But I rather incline to the hypothesis, 

 that the cavity of the ecthoreum, in its primal inverted con- 

 dition, while it yet remains coiled up in the cnida, is 

 occupied with the potent fluid in question, and that it is 

 poured out gradually within the tissues of the victim, as 

 the evolving tip of the wire penetrates farther and farther 

 into the wound. 



I do not think that the whole range of organic exist- 

 ence affords a more wonderful example than this of the 

 minute workmanship and elaboration of the parts; the 

 extraordinary modes in which certain prescribed ends are 

 attained, and the perfect adaptation of the contrivance to 



