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Table of Contents 



PLANT GROWTH SUBSTANCES 



The History and Nature of Plant Growth Hormones 3 



A. J. Haagen-Smit, California Institute of Technology 



The Synthetic Auxins: Relation Between Structure and Ac- 

 tivity 21 

 Kenneth V. Thimann, Harvard University 



Growth and Structure of the Primary Wall 37 



Thomas Kerr, United States Department of Agriculture Experi- 

 ment Station, Beltsville, Maryland 



Mechanisms of Cell Elongation 43 



Hans Burstrom, University of Lund, Sweden 



Control of Evolution and Life Processes in Plants 57 



Albert F. Blakeslee, Smith College 



Twenty Years of Plant Hormone Research 67 



F. W. Went, California Institute of Technology 



Plant Hormones in Practice 81 



P. W, Zimmerman, Boyce Thompson Institute for Plant Re- 

 search 



GROWTH SUBSTANCES IN PLANT METABOLISM 



The Study of Growth Substances in Plant Metabolism 93 



R. H. Burris, University of Wisconsin 

 Changes in Metabolism During Growth and Its Inhibition 97 



K. V. Thimann, W. D. Bonner, Jr., and G. S. Christiansen, 



Harvard University 

 Stimulation of Respiration in Relation to Growth 105 



George S. Avery, Jr., Brooklyn Botanic Garden 



65633 



