Concanavalin A (Con A), a plant lectin, has become an object of extensive research not only for the biochemist, but also for the bi­ ologist, biophysicist, pathologist, immunologist and others. On April 19-20, 1974 a group of scholars from four continents met on the campus of the University of Oklahoma for an International Symposium on Con A. This volume contains all lectures presented by the invited speakers on this occasion, as well as the abstracts for all shorter technical papers which were presented. Further, the edi­ tors invited additional contributions from a few selected laboratories to cover the areas not covered in the symposium itself. This volume then reports the present status of research with Con A. In a sense it is encyclopedic and should be a useful reference tool to the worker in this field. The newcomer to this area will find that a careful study of this book will bring him up-to-date with the latest techniques, ap­ proaches and the "state of the art" in this specialized area of re­ search, as well as with traps and ensnarements in which he need not get entangled again. Starting at the molecular level and advancing from there to the organismic level as well as to a number of highly specialized areas, this volume presents the most complete survey of research findings with Con A available today. The editors wish to acknowledge the generous financial support provided by the University of Oklahoma through its President, Dr.