Five years ago, a new system of classification of the various types of diabetes was proposed. This publication provides an inte­ grated picture of the latest information on the similarities and dissimilarites of two types of diabetes. It contains contributions from morphologists, physiologists, biochemists, immunologists, pathologists, geneticists, clinicians and epidemiologists. In the first section, the basis for the present classification and its limitations are discussed. In addition, there is a discussion of gestational diabetes and heterogeneity of some sub-classes of diabetes. The next section deals with genetics and immunology. The third section discusses abnormalities of insulin secretion and act ion on both the receptor and post . . . receptor levels. The role of gastrointestinal peptides in Type I and Type II diabetes is also considered. In the last section, both types of diabetes are compared with respect to diabetic complications. The closing sec­ tion summarizes the present status and offers a stimulating view of future development. We hope that this book will be a useful source of information for both researchers and practicing clinicians. M. Vranic G. steiner C. H. Hollenberg v ACKNOWLEDGEMENTS The symposium from which this volume arose (June 28-29, 1984) was organized by the Banting and Best Diabetes Centre, University of Toronto. We would like to express our appreciation to the following sponsors: Ames Educational Institute, Ayerst Laboratories, Becton Dickinson Canada Inc. , Canadian Soft Drink Association, Connaught Laboratories Limited, Connaught Novo Ltd. , Eli Lilly Canada Inc.