■2i0 CTEXOniOR.E. Tart II. 



ami Polypi have boon known Xo do : that is, by tni-ninir insitlo out. and at the 

 sanio time sHdiug through its own base, like the inversion or eversion oi' the 

 finger of a glove, or the feelers of a i?nail : but nothing of the kind occurs. In 

 the first place f/ic thread is solid and therefore demands a mode of extension cor- 

 relative Avith this pecidiarity. and a mode, too, which is typically difl'erent from the 

 method by eversion. "We must confess to having been completely taken by surprise 

 when we discovered that part of the cell opposite to the base of attachment gaping 

 wide open (^i'/}/>'. S. and 11 el, as if a segment of a sphere had been cut off, and 

 the thread, more or less uncoiled, thrust out, directly from its point of attachment, 

 freely into open space. Sometimes the thread was partially extended : bttt the 

 aperture of the cell was closed around it (^-T///--'. 0, 7. 0, 12). and, as in the first 

 case, it was the free end of the lasso which projected. It might be supposed that 

 the extension was effected by the contraction of the cell wall, or by pressure from 

 surrounding parts, or from behind, were it not that the cell is seen to open widely, 

 drawing back as if by means of retractor muscles, in order to let the lasso spring- 

 out, through the broad-spread aperture. Xo amoiuit of compression can straighten 

 out. or even partially extend, the thread ; but this is evidently done by its own 

 inherent power, the mouth of the cell simply gaping to let it pass. This must of 

 necessitv be the case, or how otherwise could the thread coil itself up and retreat 

 into the cell, as we have seen hundreds, and we might say thousands of them do ? 

 At one time the tentacle was as if covered by short, curly hairs, and the next 

 moment the little cttrls had disappeared, like magic. After the thread is out. the 

 cell closes or remains wide open {Fiffs. 3, 4. S). and contracts more or less upon 

 itself, the wall thickening according to the amoimt of contraction. 



After the foregoing description, it hardly need be remarked that the l)ase by 

 which these cells {Fiff. 13 h) are attached to the subjacent outer wall [c] of the 

 tentacle is the same side on which the lasso-thread has its connection [Fit/s. 1 to 

 12 c) ; and therefore the latter can never be wholly extruded, unless the vesicle 

 turns inside out. The thickness of the lasso is not only tmiform from base to 

 tip, but it does not change either by extension or by contraction. There is much 

 difterence between the degree of consistency of the wall of the cell and the 

 lasso-thread, as may be demonstrated by allowing decomposition to set in. when 

 the wall will disappear altogether, before the thread shows the least sign of decay 

 [Fiff. d). As to the manner of proceeding when these coils have arrested any 

 foreign l>ody, we have made no positive observations : we only know. that, as far as 

 their tenacity of hold is concerned, they chng as pertinaciously to a smooth glass 

 rod or a well-polished needle as to any other body ; not by coihng the tentacle 

 around them, but by simple adhesion of the thread itself; and this is the more 

 remarkable, since the latter is not only short, but perfectly smooth, possessing none 



