Plant cells contain various types of plastid, the best known among which is the chloroplast. Apart from their predominant interest for the work on photo synthesis, however, chloroplasts have attracted considerable attention for other reasons. This pertains to extranuclear inheritance of cell organelles and, particularly important for this series, to the participation of chloroplasts as discrete and partly autonomous cell constituents in the developmental biochemistry of plants. This volume is composed of articles by investigators who are actively involved in work on various aspects of research on chloroplasts. Each author has independently covered and analyzed as comprehensively as possible the particular aspects assigned to him. This has the advantage of bringing out many different facets of the situation, though some overlapping has-to be taken into account. We are sure that this volume will enable the reader to gain a broad theoretical and experimental basis for the understanding of the development of chloroplasts and the relationship between plant cells and these organelles."

The subject of this book has not been treated comprehensively before. For many years I have hesitated to attempt a monographic presentation because I felt uneasy about the idea of delineating something I am not sure about myself, and I felt it might be rash to try to integrate what seemed-and largely still seems-to consist of a heap of tessera not fitting together. The conviction won over, however, that the many details accumulated thus far call for some order now, and that an appraisal of where we stand would be appropriate. This book, I hope, can fill a gap barring the way to further progress in the field. It is not only a compilation of details but also an attempt to delineate the first outlines of a picture-blurry, obscure, and controversial as it must appear. The imagination of the research worker will be aroused, I hope, and stimulate further progress. In addition to data widely dispersed in the literature much unpublished material has been included. The limited space available prevented me from giving all the details known. The subject is also linked to many neighboring fields of study, but these relationships and their ramifications could not be discussed at length. This is a minor shortcoming, however, compared with our great ignorance of the subject in general.