PREFACE 

 to Volume II, Part 2 



This volume brings to completion the review of Photosynthesis and Re- 

 lated Phenomena which the author rashly undertook to prepare, for his own 

 orientation, in the summer of 1938. Two months at Woods Hole, with its 

 splendid hbrary, seemed, at that time, an adequate period to complete the 

 undertaking; and Interscience Publishers temptingly offered to publish 

 the result in book form. Seventeen years and 2000 printed pages later, it 

 is time to stop — even if this closure has to come in the midst of rapid and 

 promising developments in several areas covered by the narrative. 



A mistake, which proved almost fatal to the completion of the task, 

 was to postpone the publication of the whole manuscript in 1943, when it 

 Avas first finished in draft form, at a time when the war had imposed a hia- 

 tus upon the progress of non-applied research. Instead, only one half of 

 the manuscript was prepared for publication at that time (and actually 

 published, as Volume I, in 1945) ; while the second half was set aside for 

 final revision until after the war. When, in 1946, the author returned from 

 the Manhattan District to the Solar Energy Research Project at the Massa- 

 chusetts Institute of Technology (to move on, soon afterward, to the Photo- 

 synthesis Laboratory at the University of Illinois), the rapidity with 

 which new research data began to accumulate made it difficult to digest 

 and fit them into the framework of the monograph. As a result, 

 the "second volume" in turn burst its confines, and became divided in two. 

 The first half (Volume II, Part 1) was published in 1951; completion of the 

 second has taken five more years. 



Chapters 31 to 34 of the present volume (II, Part 2) follow the original 

 outline, bringing to a close the discussion of Kinetics of Photosynthesis 

 begun in Chapter 25. Chapters 35 and 36 deal with two areas of knowledge 

 that have been vastly enlarged since 1945 — the Photochemistry of Chloro- 

 phyll (in solution and in chloroplast preparations), and Chemical Path of 

 Carbon Dioxide Reduction. Chapter 37 was originally intended as a 

 catch-all for new information in the various areas covered by Volumes I 

 and 11,1 ; but in the course of preparation, division into four parts became 

 advisable: 37A (Structure and Composition of Chloroplasts) , 37B (Chem- 

 istry of Pigments), 37C (Spectroscopy and Fluorescence of Pigments), 

 and 37D (Kinetics of Photosynthesis), the latter bringing up-to-date, 



