Histamine

Natural Auxins, consists of seven papers. Their consensus is that, while indole-3-acetic acid is still to be considered a naturally occurring auxin of great importance, it is only one; a number of other indole-containing compounds, as well as less clearly identified substances, may also act as auxins in normal growth. These papers also bear witness to the immense value of partition paper chromatography as an analytical tool. Group II, Chemical Structure and Biological Activity (ten papers), confronts a basic problem of pharmacology. Many generalizations have been made concerning the molecular characteristics involved in auxin action, and they are further extended here. Much of the importance of this work is based on the hope that such generalizations will hasten the identification of the "receptor sites" at which auxins are presumed to act. The seven papers in group III, Metabolism and Mode of Action, are concerned either with the degradation of auxins or with changes in metabolism following auxin treatments, or both. Some of the aspects of metabolism discussed are water uptake, peroxidase activity, ion absorption, and sulfhydryl metabolism. Group IV, Applications of Kinetics to Auxin-induced Growth, comprises two papers presenting diametrically opposed views on the applicability of enzyme kinetics to the study of growth. The Wye conference may have been the last of its kind at which auxins so dominated the proceedings. The kinins, or cell-division factors, and the gibberellins, a group of powerful stem-elongation factors apparently unrelated to auxins, have recently attracted great attention. In keeping with the principle that the more the merrier, they should bring fresh vigor, information, and confusion into a field already well supplied with all three.