we find anywhere in nature, living or dead, below the level of human art. Haeckel’s good genius brought him to these radiolaria. Until the winter of 1859-1860 he knew very little about them. When a radiolarian dies its soft body naturally melts away and perishes. But the art-work of its life, the star or shield of flinty matter, remains; it either sinks to the bottom or is washed ashore, where numbers of them may accumulate. If a pinch of mud or sand from the shore is put under the microscope the observer will see lovely artistic fragments, and ask what is the meaning of the miracle. Ehrenberg, the venerable Berlin microscopist, was the first to have the experience. He was not in the habit of going to the sea himself, but had specimens sent to him, and found in them shells of the radiolaria. Though they were so small, their artistic quality seemed to him to be so great that he assumed they were built by very advanced animals of the star-fish or sea-urchin type. That there were unicellular protozoa with a simple gelatinous body and no higher organs he stoutly denied, and he had the support of his leading contemporaries everywhere. But his colleague, Johannes Müller, who fished in the sea himself, came across living specimens in the Mediterranean in the first half of the fifties. It appeared that they were really very lowly animals at least. Müller christened them the radiolaria, classified the fifty species that he discovered, and at his death left the subject well prepared for the first student who should go more fully into it. His final work on them did not appear until after his death, in 1858, the sunset-glow of his brilliant scientific career. Perhaps he would have gone more deeply into the mysteries he had encountered but for a curious accident. Just as he discovered the subject, two years before his death, he had a terrible experience. The ship in which he was returning from a holiday in Norway was wrecked. A favourite pupil of his was drowned, and he himself narrowly escaped by swimming to land. After that he could not be induced to enter a boat during his last trips to the sea, and so the thorough study of these most graceful inhabitants of the Mediterranean was abandoned. But when Haeckel fished at Villefranche with Kölliker of Würtzburg, and Müller was at Nice, he was urged by the master, as a kind of testamentary injunction, that “something might be done” with the radiolaria. And when he fished up a pretty crown of socially-united radiolaria on first rowing over the Messina harbour, he thought it would be a grateful offering to the memory of the dead hero of his zoological dreams to continue the study of the radiolaria. At once he seemed to enter the treasure-house of a fairy tale. When the campaign was ended in the Messina harbour in April, 1860, he had discovered no less than 144 new species, and each species proved a fresh master of decorative art. At the same time he studied the nature of the gelatinous body.