a forum at which researchers might expose and comment progress in their work over the last few years. Speakers were invi ted and their contri buti ons ordered ina number of sessions, each of which was centered on a particular topiC. Much of the benefit came from ensuing discussion sessions which were conducted with much competence and expertise by Anderson, Ben-Arie, Goren, Morgan and Osborne. All of these colleagues are recognized leaders in ethylene research today and the organizers owe a very special gratitude to them for their substantial contribution to the programme. It is well to remember the friendly atmosphere, so essential to the success of the whole meeting and so much enjoyed by every partiCipant. Prompt publi ca tion of the papers was made possi ble by the camera-ready procedure offered by the publisher.