MIMICRY. 457 



As proving the great caution which is necessary before dog- 

 matically asserting anything more than " suggested or probable 

 mimicry" with reference to the preceding instances of simulative 

 resemblances in animals and plants, it may be well to record 

 some cases of what may be considered as 



Suggestive but Disputed or Mistaken Mimicry, 

 Prof. Semper, when staying in the Balearic Islands, found 

 among the polypes of a coral (Cladocora ccespitosa) Annelids be- 

 longing to the genus Myxicola, which lived in long mucilaginous 

 tubes which they had formed in the rifts of the coral. " As long 

 as no light was thrown upon them they protruded themselves just 

 so far as that the top rim of the corona of tentacles was on a level 

 with the tentacles of the polyps, so that the worm and the polyps 

 were both extended ; the coral itself presented a perfectly level 

 surface of cups. Moreover, the funnels of Myxicola were of 

 precisely the same chocolate-brown colour as the polyps ; and, 

 when fully extended, the interior of the funnel formed by the 

 tentacles looked exactly like the oval disc of one of the neigh- 

 bouring polyps, for the radial pinnules were in the same position 

 as those lines which, on the oval disc of the polyp, radiate towards 

 the narrow central oval slit ; in the Myxicola a small central slit 

 was observable, and all the parts which corresponded so exactly 

 in size and position also displayed exactly the same colouring of 

 greenish grey, with radial lines of a lighter hue and a narrow 

 white streak in the middle. In short, the resemblance in size, 

 position, and colour of every part of the two creatures was so 

 perfect that for a long time I took the corona of the Annelid for 

 a polyp, until, by an accidental blow, I caused all the Myxicolce 

 of a large coral-stock to shrink suddenly into their tubes, though 

 it was not severe enough to induce an equally rapid movement in 

 the polyps of the apathetic Cladocora." At the time the Professor 

 "felt an almost childish delight at having detected so flagrant an 

 instance of protective mimicry/' but soon found reason to doubt 

 this interpretation of the facts. He subsequently found a marine 

 Sponge in which hundreds of this same Myxicola were living, 

 but the Sponge was coloured very differently from the Annelida, 

 so that no protection was offered. Seeking it in other spots, he 

 found the Myxicola almost everywhere, " on the rifts of rocks 



