There is little need to emphasize the importance of membrane-linked enzymes parti­ cipating in phospholipid, sterol, protein, and glycoprotein synthesis or in the synthesis of bacterial cell wall. Chapters on these topics constitute the core of the second volume of The Enzymes of Biological Membranes. In addition the volume contains an elegant chapter on galactosaminyl and galactosyl transferases in virus-transformed cells and separate chapters on glucose-6-phosphatase, pyruvate oxidase, UDP­ glucuronyl transferase, and the role of platelet membrane enzymes in hemostasis. In all there are well over one hundred membrane-linked steps in these processes, and we owe much to the authors for providing us with a balanced, informative, and compre­ hensive account of some of the most complicated biosynthetic reactions. The treatment varies from chapter to chapter as dictated by the state of the field. Well characterized enzymes are reviewed in individual chapters while lesser known ones are discussed within the framework of biosynthetic pathways. In each case, review of present knowledge and identification of areas offuture research are equally important aims of the work. The gracious collaboration of authors in meeting deadlines and providing help with the indexes is gratefully acknowledged. My warmest thanks are also due to the staff of Plenum Press and to Miss Helen Hartzog for their help.