These Proceedings of the Midwest Conference on Endocrinology and Metabolism are being published by Plenum Press for the first time. Earlier Proceedings in the series were published by the University of Missouri at Columbia. The shift to an internationally recognized publisher reflects the considerable growth in stature that the Midwest Conferences have undergone since their inception nine years ago. Originally concerned only with the endocrinology of the thyroid, the Conferences now explore other endocrine areas. Efforts are made to assemble a panel of speakers selected from different sub-disciplines within endocrinology for the purpose of addressing a common problem. The Ninth Conference typifies this approach. The format used in recent Conferences is not unique, but is unfortunately encountered too rarely.

A few prominent scholars are invited to come together to expound their findings and concepts in considerable depth, and to participate in a discussion which, together with the formal presentation, is published in the Proceedings. The discussion, noted for its unhurried nature, permits wide participation by the audience. The subject of the Ninth Conference is one which is basic and important not only to endocrinology but also to biology in general. Many, possibly most, life processes change in a rhythmic fashion, with similar states recurring at regular time intervals. This rhythmic property of living systems expresses itself as a recognizable and definable pattern or "time-form" in a manner equivalent to the more customary spatialform.

Traditionally, biologists have given major attention to problems relating to spatial-form; and we now have reached a point where we can comfortably comprehend the whole animal in terms of how various subcomponents fit together in three dimensional space. We also realize that patterns of process or change that occur within animals at the molecular, micro-, and macro-levels must also fit together in a similarly meaningful fashion to give form in the time dimension. However, critical description and analysis of "time-form" is a more recent development, and we are now beginning to appreciate the magnitude of complexity of living systems when considered in terms of this dimension. The Editors and contributors hope that this volume will assist the reader in achieving a useful overview of the "time-form" dimension in general and in relation to several specific endocrine areas.