. Corals and coral islands. Coral reefs and islands; Corals. HYDRO IDS. 77 long. It has the form of a polyp, with long slender tentacles ; and, besides these tentacles with their lasso-cells, it has no special organs except a mouth and a tubular stomach. Like the fabled Hydra, if its head be cut off another will grow out ; and any fragment will, in the course of a short time, become a perfect Hydra, supplying head, or tail, or whatever is want- ing : and hence the name given to the genus by Linnaeus. The Hydra is the type of a large group of species. It buds, but the buds drop off soon, and he
. Corals and coral islands. Coral reefs and islands; Corals. HYDRO IDS. 77 long. It has the form of a polyp, with long slender tentacles ; and, besides these tentacles with their lasso-cells, it has no special organs except a mouth and a tubular stomach. Like the fabled Hydra, if its head be cut off another will grow out ; and any fragment will, in the course of a short time, become a perfect Hydra, supplying head, or tail, or whatever is want- ing : and hence the name given to the genus by Linnaeus. The Hydra is the type of a large group of species. It buds, but the buds drop off soon, and hence its compound groups are always small, and usually it is single. But other kinds multiply by buds that are persistent, and almost indefinitely so ; and they thus make mem- branous coralla of considerable size and often of much beauty. The species figured on p. 78, the Hydrallmania Falcata, is one of them ; in allusion to its deli- cate plumes, it is called Plumu- laria. Along the branches, there are minute cells, each of which was the seat of one of the little Hydra-like animals (in this not a fourth of a line long), and usually with short tentacles spread out star-like. Other kinds are simple branching threads, and sometimes hvuka. the cells are goblet - shaped and terminal. The Tubulariae grow in tufts of thread-like tubes, and have a star-shaped flower at top, often half an inch in diameter, with a proboscis-like mouth at the centre. In Coryne, a closely-related genus, the tentacles are shorter, and somewhat scattered about the club-shaped or probosciform head of the stem, so that the animal at top is far from star- shaped or graceful in form ; it is in fact a very clumsy unshapen thing for a Radiate. To the animal of the Coryne, that of the very common, and often large, corals, called Millepores, is closely related, as first. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appeara
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