Sponge
2 of the 7 encyclopedias on this shelf carry an entry for Sponge. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
spunj, a marine animal found attached to rocks at the bottom of warm seas. Simple fresh water sponges may be found on logs and stones in our lakes and rivers. They are mistaken easily for green or brown mosses. They have no particular value. Another family of sponges, represented in the Philippines, appears to be made of spun glass. One of the most beautiful is the Venus' flower basket. Commercial sponges have a silky skeleton of fine fibres apparently felted together. In addition to the porous nature of the skeleton, regular channels may be seen along which the living animal drives a current of water by means of innumerable hairs or cilia. The sponge feeds on microscopic animals and plants arrested as the current passes. No animal is known to eat a sponge, though many find homes in its shelter. The most valuable sponge fisheries are in the Mediterranean, the Red Sea, and the coast waters of Florida and the Bahamas. Sponges are taken by rakes dragged from a boat, or by divers. They resemble pieces of beef liver at first. One can squeeze out the soft parts easily in the hand, but sponges are piled up usually until the soft tissues decay. They are then pressed, washed, dried, sorted, trimmed, possibly bleached, and sent to market. The softer, finer, more durable and elastic a sponge, the greater its value. A fine sponge the size of a plum may be worth several times as much as a large, coarse one the size of a muskmelon. The island of Aegina is the center of the Mediterranean sponge fisheries. A collecting outfit consists of a small sloop for several men. First of all, there is the captain. Three divers in armor take turns in descending. Two men in charge of hose and an air-pump drive air to the diver. A third man holds the life cord by means of which the diver gives signals. The diver fills his lungs repeatedly, closes his armor, seizes a twenty-five pound slab of marble to give himself increased weight, and plunges boldly down to a depth of anywhere from fifteen to forty fathoms. He works hastily, tearing the sponges from the rock and cramming them into a bag carried in front of him like a workman's apron. He is able to remain at the bottom about two minutes. He then gives a signal and is drawn to the surface. The Greek sponge fisher does not like to work for wages. He prefers to be paid according to his catch. London merchants purchase most of the sponges from the Mediterrean and Red Sea fisheries. The city is the world's headquarters for sponges. The Bahama sponge fisheries are of importance. The headquarters of the Bahama fisheries are on New Providence Island. These fisheries are also under British management. It is estimated that 500 vessels and 3,000 men find employment, and that $150,000 a year is paid out in wages. The waters are so clear that the sponges may be seen on the bottom at a depth of sixty feet. They are scraped up with rakes. Key West and Tampa Bay, Florida are centers of the American sponge fisheries. The fishers are mainly negroes. They go out in a sloop and pair off, two and two in rowboats. One man kneels in the stern with a water glass. When he sees a sponge on the bottom, he signals to the rower to stop. He pulls off the sponge with a three-pronged hook at the end of a slender pole from twenty to fifty feet in length. Incredible numbers of sponges are brought ashore. They form piles like haystacks in a meadow. Florida sponges of the best quality sell as high as five dollars a pound. Of late the American waters have been invaded by Greek sponge fishers from Aegina. The sponge crop of Florida for 1907 was valued at $1,500,000. See Key West ; Pearls 2026 Editor's Note: This page uses language about race that was commonplace when the book was published and is offensive by today's standards. The text has been left exactly as it was printed, rather than cut or softened, so that the historical record — including how ordinary such language once was — is preserved. (Ed: BR 2026-07-22)
Collier's New Encyclopedia (1921)
Spongida, a horny substance valued for its ready imbibition of water, and consisting of the keratode skeleton of certain Protozoa or lowest animals. A sponge is thus a colony of living animals. Such a colony communicates with the outer world by means of certain openings (capable of being closed at wil will), traceable in an ordinary sponge, and of which the larger are named oscula and the smaller pores. By the latter, currents of water are continually drawn into the sponge, while through the oscula currents are as continually discharged. These currents are kept up through the action of the minute vibratile processes named cilia, which are limited usually to certain spaces of the canals named ciliated chambers. The main use of this circulation in the sponge is evidently nutritive. Particles of food are thereby swept into the organisms, while oxygen is also inhaled and effete matters exhaled. Sponge reproduction is effected by means of specially developed masses of protoplasm named spores, which are formed in autumn, and which on liberation in spring are found to contain small reproductive particles, which after a free existence develop into sponges. Sexual reproduction is represented by the union of certain cells representing ova or eggs, and other cells representing spermatozoa. After fecundation a sponge-egg undergoes the stages of segmentation common to the developing eggs of all animals, till the morula or mulberry stage is reached. Thereafter the egg becomes elongated and swims freely about in the water. An internal cavity is next formed, this cavity communicating by a mouth externally, and being bounded by two layers (ectodern and endoderm). In this stage the young sponge is a gastrula. Latterly the outer cilia disappear, internal cilia are developed, and the sponge ultimately fixes itself, and circulation is established. Sponges are classified either as the kerag., tosa (horny), silicea (flinty, e. "Venus's flower basket," or euplectella), and calcarea (e. g., sycon). A more philosophical arrangement divides the sponge class into families: (1) Fibrospongiæ (fibrous, including silicea); (2) Myxospongia (Halisarca); Calcispongiæ (e. g., sycon and calcareous generally). Fossil sponges are of frequent occurrence. The sponges of commerce come from the Eastern Mediterranean Sea, the West Indies, and the coasts of Florida. In the Archipelago, Crete, Cyprus, on the coasts of Asia Minor, Syria, Barbary, and the Bahama Islands, sponge fisheries constitute a very important industry. The finest sponges are obtained in Turkish waters. Sponges of a coarse texture and large honey-combing are found all along the coast of Tripoli and Tunis. The West Indian trade is of importance. The Bahamas and the coast of Florida are the best fishing grounds. The qualities most in commercial demand are "wool," "reef," and "velvet"; the other kinds go by the names of "boat," "silk" or "glove," "grass," "hardhead," "mixed," "yellow," and "refuse." West Indian sponge is harsher, coarser, and less durable than its Mediterranean congener. About 2,250 men are engaged in Florida sponge fishery, and 156 vessels are employed. oyed. The fishing is generally confined to the S. W. part of the coast and reefs and shoals between St. Mark's and Anclote Keys. The methods employed in the fishery differ greatly from those employed in the Mediterranean, where divers go down and bring up the sponges. Small