The one-celled long and slender diatom, up close: discovered in 1703 with the invention of the microscope. We observe them magnified 10,000 times: water expelled through the skeleton, mucilage constantly emitted, allowing it to glide. Their energy comes from sunlight. They divide and disperse. The narrator, conversing with a young woman, says their remains cover one-third of the earth's surface. They have uses in petroleum, explosives, and polish. Some live... see more