GORGONIA, in natural history, a name given by some writers to coral, on occasion of its supposed change from a soft substance to an absolute stone, on being brought out of the water into the air: but this is known now to be a fabulous opinion, coral being as hard while growing to the rocks as when it has been ever so long out of the sea.
The gorgonians are a genus of zoophytes, which formerly were called ceratophytons, and are known in English by the names of sea fans, sea feathers, and sea-whips. Dr Linnaeus and Dr Pallas consider them as of a mixed nature in their growth, between animals and vegetables; but Mr Ellis has clearly proved that they are true animals of the polype kind, growing up in a branched form resembling a shrub, and in no part vegetable. They differ from the fresh-water polype
in many of its qualities, and particularly in producing from its own substance a hard and solid support, serving many of the purposes of the bone in other animals. This is formed by a concretizing juice thrown out from a peculiar set of longitudinal parallel tubes, running along the internal surface of the fleshy part: in the coats of these tubes are a number of small orifices, through which the osseous liquor exudes, and, concretizing, forms the layers of that part of the hard annular circles which some, judging from the consistence rather than the texture, have erroneously denominated wood. The surface of the gorgonia is composed of a kind of scales, so well adapted to each other as to serve for defence from external injuries: and the flesh, or, as some have called it, the bark or cortex, consists of proper muscles and tendons for extending the openings of their cells, for sending forth from thence their polype suckers in search of food, and for drawing them in suddenly and contracting the sphincter muscles of these starry cells, in order to secure these tender parts from danger; and also of proper secretory ducts, to furnish and deposit the osseous matter that forms the stem and branches as well as the base of the bone. Mr Ellis affirms, that there are ovaries in these animals, and thinks it very probable that many of them are viviparous.