THE
POPULAR SCIENCE
MONTHLY.
SEPTEMBER, 1873.
| THE GLASS-SPONGES. |
By Rev. SAMUEL LOCKWOOD, Ph. D.
MY attention was absorbed in the study of an object contained in a vessel of sea-water that stood upon the table. It was clad in a suit of vermilion velvet, which, with its branching form, made it not unlike the precious red coral of the Mediterranean. I had been trying with a lens to see the water-current leaving the exhaling orifice. Observation was arrested; for it had become evident that the heated condition of the water had smitten my little beauty with death. "Please tell me the name of that pretty plant," said a visitor. The reply was: "Sir, that is not a vegetable, but an animal structure. It is a dying sponge." The question has been long mooted, whether the sponge was an animal or a plant. In Japan it is called "sea-cotton;" and, until recently, this vegetable view was held even in scientific circles. Prof. H. James Clark, the learned author of "Mind in Nature," so long ago as 1857, unfolded with remarkable clearness the peculiar cell-structure of the sponge. Last year an English naturalist, H. J. Carter, fed a living calcareous sponge with indigo, then made out the cells with the coloring-matter contained. He declares himself to have fully confirmed what Prof. Clark had written. Both agree in regarding the sponges as a group in that division of the animal kingdom known as the Protozoa, and nearly allied by their uniciliated cells to the Flagellate Infusoria. These infusoria are very minute animalcules, which have certain cilia, or hair-like appendages, by which, with a lashing motion, they propel themselves through the water. Each sponge-cell has one lash, or cilium. Indeed, this cell has a sort of individuality of its own, and yet millions of these almost infinitesimal one-celled beings are united to make up the one zoological individual known as a sponge. But, as the sponge-mass is fixed, and cannot travel, why should its cells be ciliated at all? Have they any whipping to do?
