I am honored by the editor's invitation to write a Preface for this volume. As a member of an older generation of plant physiologists, my lineage in plant respiration traces back to F. F. BLACKMAN through the privilege of having M. THOMAS and W. O. JAMES, two of his "students," as my mentors. How the subject has changed in 40 years In those dark ages B. 14C. most of the information available was hard-won from long-term experiments using the input-output approach. Respiratory changes in response to treatments were measured by laborious gas analysis or by titration of alkali from masses of...