This work is a collection of short reviews on membranes and transport. It portrays the field as a mosaic of bright little pieces, which are interesting in themselves but gain full signif­ icance when viewed as a whole. Traditional boundaries are set aside and biochemists, biophysicists, physiologists, and cell biologists enter into a natural discourse. The principal motivation of this work was to ease the problems of communication that arose from the explosive growth and interdisciplinary character of membrane research. In these volumes we hope to provide a readily available comprehensive source of critical information covering many of the exciting, recent developments on the structure, biosyn­ thesis, and function of biological membranes in microorganisms, animal cells, and plants. The 182 reviews contributed by leading authorities should enable experts to check up on recent developments in neighboring areas of research, allow teachers to organize material for membrane and transport courses, and give advanced students the opportunity to gain a broad view of the topic. Special attention was given to developments that are expected to open new areas of investigation. The result is a kaleidoscope of facts, viewpoints, theories, and techniques, which radiates the excitement of this important field. Publication of these status reports every few years should enable us to follow progress in an interesting and easygoing format. I am grateful to the authors, to Plenum Publishing Corporation, and to several of my colleagues for their thoughtful suggestions and enthusiastic cooperation, which made this work possible.