Colin Stearn has been a professor in the department of Geological Sciences and its successor, Earth and Planetary Sciences, at McGill University, Montreal, since 1952. He retired from teaching in 1993. His research interests have included the Silurian and Devonian stratigraphy of the Western Canada Sedimentary Basin, the Arctic Archipelago and the Hudson Bay Lowland. His interest in the nature of mid-Paleozoic reefs has been focused on their principal constituents, the stromatoporoids. A complete taxonomic revision of the genera of Paleozoic stromatoporoids with coauthors Webby, Nestor and Stock is at present in press. In the seventies and early eighties he and his students, worked on growth and destruction of modern reefs in Barbados. He is an author of "Paleontology: the Record of Life" and three editions of "The Geological Evolution of North America".He is an Emeritus Professor of McGill University living at 65 Aberdeen Road, Kitchener, Ontario, N2M 2Y4.