FOREWORD 



This monograph is the printed record of a symposium on the 

 Structure of Protoplasm presented under the auspices of the Ameri- 

 can Society of Plant Physiologists at Philadelphia on December 30, 

 1940. 



The meeting was held under the Presidency of Dr. F. P. Cullinan, 

 with Dr. William Seifriz as chairman. The symposium was the 

 partial fulfillment of a plan, long held by the chairman, for a series 

 of lectures on the structure of matter in which physicists and chem- 

 ists would build structural units to be used by biologists in an 

 attempt to construct a mechanism having some of the properties of 

 a living system. Though no physicists or chemists in the strict sense 

 actually took part in the symposium, yet several were indirectly 

 involved; thus Professor Herbert Freundlich, who was invited to 

 attend but could not come, offered a paper on Thixotropy which 

 proved to be his last manuscript. Another chemist, Dr. Linus Paul- 

 ing, has made a substantial contribution to the Monograph by aiding 

 in the writing of the Introduction. Throughout the chapters is 

 evidence of assistance from other physicists and chemists, notably 

 Dr. W. T. Astbury, Dr. H. Mark, and Dr. Kurt Meyer, two of whom 

 have made brief, last-minute contributions of their own which have 

 been put in a Supplement. 



This volume is the first in what is planned to be a series of mono- 

 graphs to be published under the auspices of the American Society 

 of Plant Physiologists. It is appropriate that the first monograph 

 should deal with so basic a subject as the structure of living matter. 

 It is the wish of the authors that this monograph reawaken among 

 American botanists an interest in a study which occupied so much of 

 the time of European botanists during the past century. It was a 

 botanist, Karl von Naegeli, who gave biology and chemistry one of 

 the first fundamental theories of protoplasmic and gel structure, 

 and it was a botanist, Fr. Weber, who established the first journal 

 devoted solely to a study of protoplasm. By inaugurating its series 

 of monographs in plant physiology, with a volume on the structure 

 of protoplasm, the American Society of Plant Physiologists takes 



