CONTENTS 



PACE 



Preface ........... v 



Conference Photograph . . . . . . . . x 



Members of the Conference ....... xi 



I. NATURAL AUXINS 



Methods for the investigation of natural auxins and growth 



inhibitors. J. P. Nitsch {Harvard) .... 3 



The distribution of natural hormones in germinating seeds and 

 seedling plants. Phyllis M. Cartwright, J. T. Sykes, and 

 R. L. Wain ( Wye) 32 



Hormones and hormone precursors in leaves, roots, and seeds. 



Joyce A. Bentley, S. Housley, and G. Britton {Manchester) . 40 



Chromatographische Untersuchungen iiber die Wuchsstoffe 

 und Hemmstoffe der Haferkoleoptile. H. Soding und Edith 

 Raadts {Hamburg) ....... 52 



Indole compounds in photoinduced plants. A. J. Vlitos {New 



York) 57 



The biogenesis of natural auxins, .S*. A. Gordon {Lemont) . 65 



Geotropic responses in roots. Some theoretical and technical 



problems. P. Larsen {Bergen) ..... 76 



II. CHEMICAL STRUCTURE AND BIOLOGICAL 

 ACTIVITY 



On the effects of /;ara-substitution in some plant growth 



regulators with phenyl nuclei. B. Aberg {Uppsala) . . 93 



On form and function of plant growth substances. H. Veldstra 



{Amsterdam) . . . . . . . • 117 



The mode of growth action of some naphthoxy compounds. 



H. Burstrom and Berit A. M. Hansen {Lund) . . ■ 134 



VII 



'5'3135 



