SPONGIA, in natural history, sponge, a genus of the Vermes Zoophyte class and order: animal fixed, torpid, of various forms, composed either of reticulate fi bres, or masses of small spines, interwo ven together, and clothed with gelatinous flesh, full of small mouths on its surface, by which it absorbs and rejects water. Between fifty and sixty species have been enumerated. S. officinalis is irregularly formed, porous, tough, lobed, and woolly : It is found in the Archipelago, Mediter ranean and Indian seas, adhering to rocks by a broad base : it is often found enclosing small stones, shells, and parti cles of sand : variety of marine animals pierce and gnaw it into irregular winding cavities, which appear on the outside by large holes higher than the rest : its co lour varies from a pale to a deep yellow ; the internal part, when cut perpendicular, consists of small tubes, composed of re ticulate fibres, and ending on the outside in an infinite number of small circular holes, which are the bibulous mouths of the animal, each of which is surrounded by a few erect pointed fibres. This is the common sponge of the shops.
S. ventilabrum, is fan-shaped, regular, soft, with reticulate woody veins, covered with pores like a honeycomb. This spe cies inhabits the Norway and American seas; is about six inches high, and five broad: exactly resembles a small Gorgo nio flabellum in its shape and ramifica tions, except that the pores are angular, and the substance is spongy.
S. cristata, Or cock's-comb sponge, is flat; erect, and soft, growing in the shape of cock's combs, with rows of little holes along the tops, which project a little. It abounds on the rocks to the eastward of Hastings, in Sussex, where it may be seen at low-water. It is commonly about three inches long, and two inches high, and of a pale yellowish colour. When put into a glass vessel of sea water, it has been observed to suck in and squirt out the water through little mouths along the tops, giving evident signs of life.
S. tomentosa, or urena, stinging sponge, or crumb of bread sponge, is of many forms, full of pores, very brittle and soft, and interwoven with very minute spines. It is full of small protuberances, with a hole in each, by which it sucks in and throws out the water. It is very com mon on the British coast; and is fre quently seen surrounding fucuses. It is found also on the shores of North Ame rica, Africa, and in the East Indies. When newly taken out of the sea, it is of a bright orange colour, and full of gela tinous flesh ; but when dry, it becomes whitish, and when broken has the appear ance of crumbs of bread. If rubbed on
the band, it will raise blisters; and if dried in an oven, its power of stinging is much increased, especially that variety of it which is found on the sea coast of North America.
S. fluviatilis, river sponge, is green, erect, brittle, and irregularly disposed in numerous branches. It abounds in many parts of Europe, in the fresh rivers of Russia and England, but particularly in the river Thames. It scarcely exhibits any symptoms of life ; is of a fishy smell; its pores, or mouths, are sometimes filled with green gelatinous globules.
So early as the days of Aristotle spong es were supposed to possess animal life ; the persons employed in collecting them having observed them shrink when torn from the rocks, thus exhibiting symptoms of sensation. The same opinion prevail ed in the time of Pliny. But no attention was paid to this subject, till Count Mar sigh examined them, and declared them vegetables. Dr. Pcysonell, in a paper which he sent to the Royal Society in the year 1752, and in a second in 1757, af firmed they were not vegetables, but the production of animas, and has according ly described the animals ; and the process which they performed in making the sponges. Mr. Ellis, in the year 1762, was at great pains to discover these ani mals. For this purpose he dissected the spongia urena, and was surprised to find a great number of small worms, of the genus nereis, or sea scolopendra, which had pierced their way through the soft substance of the sponge in quest of a safe retreat. That this was really the case, he was fully assured of, by inspecting a number of specimens of the same sort of sponge, just fresh from the sea. He put them into a glass filled with sea water : and then, instead of seeing any of the little animals which Dr. Peysonell described, he observed the papilla, or small holes with which the papilla are surrounded, contract and dilate themselves. He ex amined another variety of the same spe cies of sponge, and plainly perceived the small tubes inspire and expire the water. He therefore concluded, that the sponge is an animal, and that the ends or open ings of the branched tubes, are the mouths by which it receives its nourish ment, and discharges its excrements.
SPOON-bill. See PLATNA.