The 9th International Conference on Plant Growth Substances was held at the University of Lausanne, August 30-September 4, 1976. This meet ing was sponsored by the National Swiss Foundation for Scientific Re search (FNRS), the Fonds Herbette of the Faculty of Sciences of Lau sanne, by several other official sources, and by a few Swiss indus tries. The conference was attended by over 420 scientists, represent ing 42 countries, with a total of 550 participants. Our 9th conference was rather different from the previous ones. The usual short submitted papers followed by a too brief discussion were replaced by three kinds of scientific communications. First in the reports, authors gave a critical analysis of a selection of broad to pics, directing their comments to new perspectives of research and me thodology. Second, the paper demonstrations, presented by over 200 scientists, induced large and fruitful discussions and ensured that personal contacts were made. Finally, during four workshops, several interesting points - introduced in the reports and paper demonstra tions - were developed and discussed.

Inhalt
I. The Wall of Growing Cells.- 1. The Molecular Structure of the Primary Cell Wall and Elongation Growth.- 2. Cellulose Metabolism and Cell Growth.- 3. Wall Extensibility in Relation to Auxin Effects.- II. Hormones Membranes.- 4. Membrane-Bound Auxin Receptors: Solubilization and Characterization.- 5. Auxin Hormone-Plasma Membrane Interactions.- 6. Interactions Between Indole-3-Acetic Acid and Phospholipids in Deuterochloroform as Determined by 1H, 13C, and 31P NMR Spectrometry.- 7. Physiologic Implications of the Hormonal Control of Ion Transport in Plants.- III. Hormone Analysis.- 8. The Application of High Performance Liquid Chromatography to the Analysis of Plant Hormones.- 9. Gas Chromatographic Identification and Quantitative Estimation of Natural Auxins in Developing Plant Organs.- IV. Auxins and Root Growth Inhibitors.- 10. Interactions in Translocation of Growth Regulators in Shoots with Special Reference to Auxin Transport as Affected by Two Inhibitors, a Morphactin and Lycoricidinol.- 11. Auxins and the Regulation of Root Growth.- 12. Root Growth Inhibitors.- 13. Growth Inhibitors in Growing and Geostimulated Maize Roots.- V. Gibberellins and Cytokinins.- 14. Some Aspects of Gibberellin Metabolism in Higher Plants.- 15. Cytokinin-Binding Proteins in Higher Plants.- 16. Cytokinin Relations in the Whole Plant.- 17. Cytokinin and Cell Metabolism.- VI. Ethylene and Other Regulators.- 18. Auxin and Ethylene and the Control of Cell Growth. Identification of Three Classes of Target Cells.- 19. On the Role of Ethylene in Aging.- 20. Phenolic Substances and Their Possible Role in Plant Growth Regulation.- 21. Some effects of Dikegulac on the Physiology of Whole Plants and Tissues; Interactions with Plant Hormones.- VII. Gravity and Light Effects.- 22. GeotropicResponse Mechanism in Root and Shoots.- 23. Ultrastructural Aspects of Georeceptors in Roots.- 24. Hormonal Regulation of Phototropism in Dicotyledonous Seedlings.- 25. Light, Rhythmus, and the Problem of Florigen.- VIII. Hormonal Control.- 26. The Hormonal Regulation of the Cell Division Cycle.- 27. Hormonal Controls of Abscission: Biochemical and Ultrastructural Aspects.- 28. Hormonal Regulators of Plant Flowering.- 29. Hormonal Relationships in Whole Plant Senescence.- 30. Growth Substances and Protoplasts.- IX. Paper Demonstrations.