General preface. Chapter 1. A backward glance (J.M. Buchanan). Chapter 2. The discovery of phosphoenolpyruvate carboxykinase. In memoriam M.F. Utter (K. Kurahashi). Chapter 3. Jeffries Wyman and Myself: a story of two interacting lives (J.T. Edsall). Chapter 4. The BAL-labile factor in the respiratory chain (E.C. Slater). Chapter 5. Experiences in biochemistry (N.O. Kaplan). Chapter 6. A half century of biochemistry (H.A. Lardy). Chapter 7. A biochemist`s view of his struggle for knowledge. Review of forty years service to science (M. Klingenberg). Chapter 8. Peter Hemmerich: an eventful life around flavins. Memoirs dictated in the last weeks of his life, August 1981 with an introductory note (H. Beinert). Chapter 9. Adventures and research (E. Lederer). Chapter 10. Recurrent luck in research (N.W. Pirie).