This new text, by a distinguished biochemical geneticist, gives the reader a wide–ranging account of the various kinds of analysis, including both classical genetical and molecular techniques, that combine to give genetics its present power and scope. The book goes on the describe and assess the progress made towards three main objectives: first, the complete description of the genetic material, including both gene structure and overall genomic organization; second, the detailed accounting for heritable variation in populations; and finally, the explanation of how the genes control the metabolism and development of the whole organism. Professor Fincham is concerned to emphasize both the amazing progress made by genetics in the analysis of biological systems and the enormous complexity of the problems still to be solved.