In recent decades critics in several countries have complained that education in agriculture, engineering and medicine has drifted away from an earlier practical orientation, becoming increasingly irrelevant to actual needs. Since existing histories have surprisingly little to say about the causes of such 'academic drift', this book develops a model of institutional dynamics which explains why different institutions have evolved closer to the worlds of 'science' or 'practice'. The model is based on a study of German agricultural colleges and the study surveys the evolution of the agricultural curriculum during the nineteenth and early twentieth centuries, as it swung back and forth between the poles of science and practice.