146 THE OCEAN WORLD. 



tells us that his Pennatula eynomorium differs from the Alcyonium 

 only in this, that the former is a movable and the latter a fixed poly- 

 pidom ; and he saw with equal clearness the connection which exists 

 between these genera and the shrub-like Gorgonia. Of the Pennatula 

 mirabiUs he had doubts whether it was not rather a species of 

 Gorgonia, until he perceived that the stem was attenuated at each 

 end, and free ; and of the Sea-pens generally, Ellis remarks that they 

 are ' a genus of zoophytes not far removed from the Gorgtonias, on 

 account of their polyp mouths, as well as having a bone in the inside 

 and flesh without.' ' On the other hand, the Gorgonise seem,' says 

 Pallas, ' with the exception of their horny skeleton, to be nearly 

 similar in structure to the Alcyon^a ; but as there are species of 

 Gorgonia which are suberose internally, and almost of a uniform 

 medullary consistence, even this mark of distinction fails to separate 

 the tribes, and we have little left to guide us in arranging these 

 esculent species excepting their external habits.' " 



" With most corallines," says Fredol, " the elementary individual, 

 in spite of the adhesion established among them, possesses a vital 

 energy all its own ; it is in some respects quite independent. They 

 have each its own particular will, which it is difficult to mistake for 

 a common will ; but it is not thus with the Pennatula. Their asso- 

 ciation consists of a non-adherent polyp, which moves obscurely, 

 it is true but still it moves. To what does this lead ? To this : 

 that the parts which they possess in common, in place of being horny 

 or calcareous that is, completely inert are fleshy, with contractile 

 powers ; that is to say, animated. Consequently, the polyp of the 

 Pennatula are less independent of each other than the coral polyp, 

 which have a central, perhaps a sensible organ, common to all, which 

 binds them to each other, giving a certain unity to their acts. The 

 Coralline polyps have no will ; the Pennatula have." 



