X PREFACE 



provide new insight into the physiological and biochemical aspects 

 of evolution. 



This volume represents an effort to bring together some of 

 this widespread and wide-ranging information, and to a modest 

 extent, to make some attempt at the organization and synthesis 

 of various facts and theories. 



Although the results of recent and current research, including 

 the author's studies on lignins and lignification, have been in- 

 corporated, this volume is not presented primarily as an advanced 

 research treatise. The future of cell wall research, both in its own 

 right and as an example of a valuable orientation in experimental 

 biology, rests with the present-day students of botany and zoology 

 who are willing to acquire understanding and proficiency in many 

 areas of science and as much with those in chemistry and physics 

 who have latterly become aware of the rich field of investigation 

 that is biology. 



To those who made this book possible, I take pleasure in ex- 

 pressing the deepest gratitude. Thanks are due particularly to 

 Professor James Bonner, California Institute of Technology; 

 Professor Arthur W. Galston, Yale University; and Professor 

 David Goddard, University of Pennsylvania; who each in his 

 own way contributed support, encouragement, and stimulating 

 ideas to the author's research on lignification. 



Thanks are also due to the students whose loyalty, help and 

 enthusiam lightened many tasks and broadened many ideas: Mr. 

 L. N. Chessin, New York University School of Medicine; Mr. 

 K. Cost, University of Minnesota; Mr. N. Goodman, Brandeis 

 University; Mr. [B. LeFevre, Armour and Co., Chicago; Dr. D. 

 Ridgeway, California Institute of Technology; and Mrs. Colin 

 Taylor, University of Rochester. 



To his wife and colleague, Barbara Siegel, the author expresses 

 his indebtedness for many years of challenging ideas and construc- 

 tive criticism. 



Material, and in no small degree, moral, support was provided 

 by the Wallace C. and Clara A. Abbot Memorial Fund of the 

 University of Chicago ; by the National Cancer Institute, National 

 Institutes of Health, United States Public Health Service (Research 



