rOSSIBLT A SURTIVING KESEMBLANCB. 403 



resemblance between the two creatures could not be disputed, 

 nor could the fact that this resemblance was perfectly nornial. 

 Among the hundreds of specimens of Myxicola which I found 

 in various pieces of coral, procured from the most various 

 localities, I never found one that had not these same points of 

 resemblance to the polyps. One day, finally, I found a marine 

 sponge in which hundreds of this same Myxicola were livinc, 

 and in every portion of it their funnels of tentacles extended 

 just to the level of the surface of the sponge ; but the sponge 

 was coloured very differently from the Annelida, so that these 

 when protruded were very easy to distinguish from the spono-e. 

 I then sough b for the Myxicola in other spots, and succeeded in 

 finding it almost everywhere ; in the rifts in rocks and in the 

 sand, between marine plants or the tubes of other vrorms — in 

 short everywhere — and wherever I examined it clo-ely it was 

 exactly of the size and colotir of the polyps of Cladocora cces- 

 pitosa. Mimioiy, it is plain, is out of the question ; the resem- 

 blance between the two creatures is simply and wholly acci- 

 dental. 



It seems to me that the obvious conclusion from all this is 

 that, under some circumstances, the most perfect and complete 

 re.?emblance between two creatm^es not living associated, may 

 originate without its being referable to the selective power of 

 mimicry, i.e. a protective resemblance. The possibility might 

 certainly, however, be conceivable that that resemblance may 

 originally have been acquired by such means, and subsequently 

 retained after the Myxicola had been enabled, by the aid 

 of some other means of protection, to establish itself in various 

 other places. We have not, however, any single analogous 

 instance to support this assumption ; besides, it should be 

 observed that all the species, without exception, of the genus 

 Myxicola have the same fiinnel-shaped arrangement of their 

 tentacles, and the colouring of their head generally harmonises 

 with that of many polyps; they are commonly brownish, 

 greenish, or red. A general resemblance between the worm 

 and the polyps is thus of common occurrence ; and as we are 

 compelled to assume other causes than selection by protective 

 tesemblance in explanation of this likeness, it will be equally 



