by NICHOLAS POLUNIN M.S. (Yale), M.A., D.Phil., D.Sc. (OXON.) Visiting Professor, University of Geneva; lately Professor of Plant Ecology and Taxonomy, Head of the Department of Botany, and Director of the University Herbarium, etc., Faculty of Science, Baghdad, Iraq. Formerly Fielding Curator and Keeper of the University Herbaria, University Demonstrator and Lecturer in Botany, and Senior Research Fellow of New College, Oxford; Macdonald Professor of Botany, McGill University; Research Associate, etc., of Harvard and Yale Universities.