William Archer (b. Co. Down 1837, d. 1897), F.R.S., devoted his life to the microscopic examination of freshwater organisms, especially desmids and diatoms. He attained a very prominent place in this branch of work among men of science. Perhaps his most remarkable discovery was that of Chlamydomyxa labyrinthuloides (in 1868), "one of the most remarkable and enigmatical of all known microscopic organisms." George James Allman (b. Cork 1812, d. 1898), F.R.S., professor of botany in Trinity College, Dublin, and afterwarls Regius Professor of natural history in the University of Edinburgh, published many papers on botanical and zoological subjects, but his great work was that on the gymnoblastic Hydrozoa, "without doubt the most important systematic work dealing with the group of Coelenterata that has ever been produced." Amongst eminent living members of the class under consideration may be mentioned Alexander Macalister (b. Dublin 1844), F.R.S., professor of anatomy, first in Dublin and now in Cambridge, an eminent morphologist and anthropologist, and Henry Horatio Dixon (b. Dublin), F.R.S., professor of botany in Trinity College, an authority on vegetable physiology, especially problems dealing with the sap. GEOLOGISTS. Samuel Haughton (b. Carlow 1821, d. 1897), F.R.S., after earning a considerable reputation as a mathematician and a geologist, and taking Anglican orders, determined to study medicine and entered the school of that subject in Trinity College. After graduating he became the reformer, it might even be said the re-founder, of that school. He devoted ten years to the study of the mechanical principles of muscular action, and published his _Animal Mechanism_, probably his greatest work. He will long be remembered as the introducer of the "long drop" as a method of capital execution. He might have been placed in several of the categories which have been dealt with, but that of geologist has been selected, since in the later part of his most versatile career he was professor of geology in Trinity College, Dublin. Valentine Ball (b. Dublin 1843, d. 1894), F.R.S., a brother of Sir Robert, joined the Geological Survey of India, and in that capacity became an authority not only on geology but also on ornithology and anthropology. His best known work is _Jungle-Life in India_. In later life he was director of the National Museum, Dublin. MEDICAL SCIENCE. Very brief note can be taken of the many shining lights in Irish medical science. Robert James Graves (1796-1853), F.R.S., after whom is named "Graves's Disease", was one of the greatest of clinical physicians. His _System of Clinical Medicine_ was a standard work and was extolled by Trousseau, the greatest physician that France has ever had, in the highest terms of appreciation. William Stokes (1804-1878), Regius Professor of Medicine in Trinity College, and the author of a _Theory and Practice of Medicine_, known all over the civilized world, was equally celebrated.