This volume provides evidence of the diversity of scientific disciplines that presently have a stake in the quest for the gene. The essays here offer challenging perspectives on some of the most fundamental concepts of twentieth-century biology. Conceptual perspectives about the gene as it is presently known provide the substance of three contributions. The examination of pre-Darwinian heredity concepts, Goldschmidt's demission of the gene, and Seymour Benzer's work on the fine structure of the gene are also explored. A critique of the "genetic program" is presented as well as modern findings about the functioning of "master genes' during embryogenesis. In the final essay, Raphael Falk reviews the material laid out in this volume. This book should be of interest to professionals and students of philosophy and the history of science, genetics, and molecular biology.