The first volume of the series, on "The Stability of the Differentiated State" received many favorable reviews from the scientific community. Many readers seem to agree with us that publication of topical volumes is a worthwhile alternative to periodic compilations of rather unrelated, though up-to-date reviews. Production of topical volumes is however, plagued with one great difficulty, that of "author synchronization." This difficulty explains the lag between volumes 1 and 2 of the series. Nevertheless we hope that the present volume will be appreciated as a valuable source of information on its central topic: How do cell organelles originate, and what mechanisms assure their continuity? Tubingen, Berlin, Zurich, \V. BEERMANN, J. REINERT, H. URSPRUNG, Heidelberg H. -W. HA GENS Contents Assembly, Continuity, and Exchanges in Certain Cytoplasmic Membrane Systems by W. GORDON WHALEY, MARIANNE DAUWALDER, aud ]OYCE E. KEPHART 1 I. The Nature of the Membrane. . . . . . H. The Assembly of Membranes . . . . . . 5 III. The Growth and Transfer of Membranes. 6 A. The Nuclear Envelopc . . . 6 B. The Endoplasmic Reticulum 13 C. The Golgi Apparatus . 17 D. The Plasma Membrane 28 E. Vacuoles and Vesicles 31 IV. Concluding Remarks 37 References . . . . . 38 Origin and Continuity of Mitochondria by ROBERT BAXTER 1. Introduction . . . . . . . . . . . . . 46 H. Mitochondrial Biogenesis: thc Machincry 46 III. Limitations of Mitochondrial Autonomy 50 IV. The Replication of Mitochondria 53 V. Discussion and Conclusion 58 Referenccs . . . . . . . . . 59 Origin and Continuity of Plastids by \VILFRIED STUBBE 1. Introduction . . . . . . . . . . . . . 65 II. Arguments for the Continuity of Plastids ."

Contains all the information a pilot needs to undertake the basic loops, rolls and spins that make up the aerobatic repertoire. The book takes the pilot through ground training, aircraft and equipment limitations, and the physical effects on the human body, to air exercises such as advanced turning, stalling, spinning and recovery from unusual attitudes. The final section contains the basic aerobatic manoeuvres such as the loop, the barrell roll, the stall turn and the snap roll, and combination manoeuvres.