At the 6th International Conference on Plant Growth Substances, held in Carleton University, Ottawa in 1968, it was decided that the 7th should be held in Czecho slovakia, following an invitation by Dr. Kutacek. Historical events intervened and in 1969 another venue was sought. An offer from the Academy of Science in Canberra was accepted by the steering committee. This left rather less time than is desirable to organize an international meeting of this nature and it was with surprise and great relief that the Organizing Committee in Canberra welcomed the arrival of 183 delegates, including a relatively large overseas contingent, to the meeting in December, 1970. The aim of these Conferences is, of course, to provide a forum for discussion of new work and recent trends, both in the lecture sessions and in conversation. Although many of those who initiated these meetings (e.g. Skoog, Went, Blackman, Bennet-Clark) were absent from the Canberra conference - some have retired -it was good to see present so many of the new generation of research workers in this field.

Section 1 Cell Extension: Models, Membranes and Wall Properties

Section 2 Rapid Action of Auxins
Section 3 Biosynthesis of Auxins
Section 4 Biosynthesis of gibberellins
Section 5 Hormones and Nucleic Acids
Section 6 Hormones and Isoenzymes
Section 7 Binding of Hormones to cell Constituents
Section 8 Inhibitors
Section 9 Gibberellins: The Cereal Aleurone Layer
Section 10 Gibberellins: Other Systems
Section 11 Cytokinins
Section 12 Ethylene
Section 13 Hormones in Relation to Senescence
Section 14 Growth and Morphogenesis
Section 15 Transport and Tropisms
Section 16 Hormones and Flowering
Section 17 Application of Glows to Hormone Studies
Index to Authors
Index to Organisms
Index to Subjects.