About the Editors Dr. K.G. Adiyodi, formerly Professor of Reproductive Physiology and Dean, Faculty of Science, Calicut University, Kerala, India and Vice-Chancellor, Cochin University of Science and Technology, Kochi, is now Public Service Commissioner to Government of India, New Delhi. A distinguished invertebrate reproductive biologist who gave the discipline of invertebrate reproductive biology a global distinctiveness and identity of its own, Dr. K.G. Adiyodi is Founder Secretary of the International Society of Invertebrate Reproduction, Founder Editor-in-Chief of the International Journal of Invertebrate Reproduction and Development, and Founder President of the Indian Society of Invertebrate Reproduction. Dr. Rita G. Adiyodi, formerly Rhodes Visiting Fellow, Somerville College, Oxford (1976 78) is Professor of Zoology at Calicut University. She served as President of the Crustacean Reprobiology and Aquaculture Bureau of India and as Vice-President of the Indian Society of Invertebrate Reproduction. Dr. Rita Adiyodi represented India on the International Committee of Comparative Endocrinology. The Adiyodis have worked extensively, over the last three decades, on the endocrinology and physiology of growth and reproduction of arthropods, chiefly crustaceans. Dr. J.R. Collier is Professor Emeritus of biology at Brooklyn College of the City University of New York, Brooklyn, New York 11210, USA. He is an invertebrate embryologist who studies the molecular biology and molecular genetics of gastropod development. Dr. Collier has a special interest in the role of cytoplasmic determinants on gene expression and embryonic determination. His research has concentrated on the embryology of the marine mud snail Ilyanassa obsoleta.