The present volume was conceived as a companion to 'Antarctic Oasis: Terrestrial environments and history of the Vestfold Hills' edited by J. Pickard and published in 1986 by Academic Press, Sydney. Pickard's book contains accounts of the Vestfold Hills' climate (N. A. Streten) and recent geomorphological history (D. A. Adamson & J. Pickard) which provide a valuable context for understanding their present day biology. Pickard also gives a history of human discovery and occupation of the Vest fold Hills. There is some overlap in the coverage, to the extent that both this volume and Pickard's book describe the terrestrial flora and fauna. The reader specifically interested in the terrestrial ecosystems of the Vestfold Hills should draw from both sources. Together, these works present a broad and descriptive account of the largest truly coastal antarctic oasis: a region that holds a unique variety of opportunities for future scientific investigation. There are several tasks I wish to accomplish here, apart from expressing my sincere thanks to the many people who have contributed to the completion of this volume. I wish to briefly introduce the Vestfolds and to list some of the features that, in my opinion, make them biologically varied, and unique in the context of other coastal ice-free areas. I wish to describe the phases of biological research in this region, including the directions that have been pursued since the 1984 symposium and to comment upon the future of the Vestfold Hills.

The present volume was conceived as a companion to 'Antarctic Oasis: Terrestrial environments and history of the Vestfold Hills' edited by J. Pickard and published in 1986 by Academic Press, Sydney. Pickard's book contains accounts of the Vestfold Hills' climate (N. A. Streten) and recent geomorphological history (D. A. Adamson & J. Pickard) which provide a valuable context for understanding their present day biology. Pickard also gives a history of human discovery and occupation of the Vest fold Hills. There is some overlap in the coverage, to the extent that both this volume and Pickard's book describe the terrestrial flora and fauna. The reader specifically interested in the terrestrial ecosystems of the Vestfold Hills should draw from both sources. Together, these works present a broad and descriptive account of the largest truly coastal antarctic oasis: a region that holds a unique variety of opportunities for future scientific investigation. There are several tasks I wish to accomplish here, apart from expressing my sincere thanks to the many people who have contributed to the completion of this volume. I wish to briefly introduce the Vestfolds and to list some of the features that, in my opinion, make them biologically varied, and unique in the context of other coastal ice-free areas. I wish to describe the phases of biological research in this region, including the directions that have been pursued since the 1984 symposium and to comment upon the future of the Vestfold Hills.

The fifth volume in this series is focused on the chemical and physical interactions between rocks undergoing metamorphism and the fluids that they generate and that pass through them. The recognition that such pro cesses can profoundly affect the course of metamorphism has resulted in a number of recent papers and we consider that it is time for a review by some of the interested parties. We hope our selection of contributors provides an adequate cross section and demonstrates some of the flavor of this rapidly developing field. A cursory examination of the volume will reveal that there are widely divergent opinions on the compositions of metamorphic fluids and on the ways in which they interact physically and chemically with the rocks through which they pass. Since our own views are extensively discussed in Chapters 4 and 8, we leave the reader to determine his own brand of the "truth. " We wish to thank D. Bird, S. Bohlen, D. Carmichael, G. Flowers, C. Foster, C. Graham, E. Perry, J. Selverstone, R. Tracy, J. Valley, and R. Wollast for their chapter reviews. Thanks are also due C. Cheverton for her editorial assistance, and the helpful staff at Springer-Verlag New York."