148 SEA-SIDE STUDIES. 



We have already seen how erroneous was the supposition 

 that Polypes paralysed their victims with a touch, and that 

 poison was secreted by their tentacles ; yet for this supposi- 

 tion there was at least the evidence of partial observation, 

 whereas, for the supposition we have now to consider, there 

 is absolutely no evidence at all. 



On a survey of the places where these "urticating cells " 

 are present, we stumble upon an unlucky fact, and one in 

 itself enough to excite suspicion. They are present in afeiu 

 Jelly-fish — which urticate ; in ActiniaB— which urticate ; and 

 in all Polypes— which, if they do not uiticate, are popularly 

 supposed to do so, and at any rate possess some pecidiar 

 power of adhesion. In all these cases, organ and function 

 may be said to go together. But the cells axe also present 

 in the majority of Jelly-fish, which do not urticate ; in Eolids 

 —which do not urticate; and in Planarias- which do not 

 urticate. Here, then, we have the organ, without any cor- 

 responding function ; " urticating cells," but no urtication ! 

 The cautious mind of Owen had already warned us that there 

 was something not quite satisfactory in our supposition ; 

 "some superadilition to the thread-cell would seem to be 

 essential to the urticating faculty," he says, when speak- 

 ing of the Jelly-fish, " since these cells are present in 

 species and parts that do not sting." It is to be regretted 

 that he was not moved by this doubt to a closer examin- 

 ation of tlie evidence on which the urticating faculty 

 rested ; he woidd assuredly have been led to the belief that 

 no superaddition to the thread-capsule wUl account for the 

 phenomenon. 



