THE 



POPULAR SCIENCE 

 MONTHLY. 



SEPTEMBER, 1873. 



THE GLASS-SPONGES. 



By Eev. 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. Ob- 

 servation was arrested ; for it had become evident that the heated con- 

 dition 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 

 6ponge." 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. Car- 

 ter, 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 Flagel- 

 late 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 ? 

 vol. m. 34 



