The bib I iography includes papers in alI fields of photosynthesis researc- from studies of model biochemical and biophysical systems of the photosynthesis mechanism to primary production studied so-cal led growth analysis. In addition to papers devoted entirely to photosynthesis, papers on other topics are included if they contain data on photosynthetic activity, photorespiration, chloroplast structure, chlorophyl I and carotenoid synthesis and destruction, etc. , or if they contain valuable methodological information (measurement of selected environmental factors, leaf area, etc. ). In many branches it has been very difficult to define the I imits of interest for photosynthesis researchers. This problem has arisen e. g. in topics dealing with the transport of gases, where - in addition to the papers on C0 transfer- some papers on water vapour transfer are included, these 2 being of general application. On the other hand, many papers dealing with the anatomy and physiology of stomata have been omitted, if the aspect of carbon dioxide or water vapour exchange has not been discussed. To maximize the value of the bibliography the references are arranged alpha betically by author's names, and each volume is provided with three indexes. The authors' index to this volume contains alI names of authors, co-authors and editors. The subject index covers only primary items chosen according to their inter est for photosynthesis researchers. In this volume its preparation was based on the paper titles, key words and abstracts.

It is generally accepted that photosynthesis, whereby solar is transformed into geobiochemical energy, is one of the most important processes in the bio sphere. When we realize that the human population, most of which is starving, wi I I double in 20-30 years, and that photosynthesis is in practice the only source (direct or indirect) of food not only for men, but for al I I iving beings, its im portance becomes even plainer. This fact was recognized from the outset of the International Biological Programme, when photosynthesis was selected as one of the principal problems to be concentrated on. The significance of the IBP in initiating a broader-based ap proach and worldwide collaboration need not be emphasized here; it is merely ne cessary to consider the rapid increase in the number of papers on photosynthesis since its inception. It is of fundamental importance for scientists working on photosynthesis to get information on what has been done in recent years in this discipl ine. Thus as complete as possible a bibl iography is badly needed. The complexity of this pro blem requires also that the progress of ecology, chemistry and physics, as far as they concern photosynthesis, be fol lowed. Such a bib I iography, covering at least the last ten years, wi I I be indispensable for final synthesis of the results of the IBP photosynthetic programme.

The Second International Congress on Photosynthesis Research took place in Stresa, Italy during June 24-29, 1971; two centuries after the discovery of Photosynthesis by Joseph Priestley in 1971. This important anniversary was celebrated at the Congress by a learned account of Priestley's life and fundamental discoveries given by Professor Robin HILL, F. R. S. Professor HILL's lecture opens the first of the three volumes which contains the contributions presented at the Congress. The manuscripts have been distributed into three volumes. Volume I con tains contributions in the areas of primary reactions and electron transport; Volume II ion transport and photophosphorylation, and Volume III carbon assimilation, regulatory phenomena, developmental aspects, and from the two special sessions of the Congress devoted to evolution and photorespiration. It is realized that this division is necessarily somewhat arbitrary since many contributions relate to more than one of the above mentioned titles. However, the large number of contributions (over 3000 typed pages) made it impossible to publish the proceedings in less than three volumes. The printing of these volumes and the organization of the Congress were made possible by a contribution from the Consigio Nazionale delle Ricerche of Italy. The generous support of the Istituto Lombardo Acca demia di Scienze e Lettere to the publication of these proceedings is gratefully acknowledged. The editors wish to express their appreciation to all the scientists who contributed the results of the investigations, for their coopera tion; and to Drs.