The history of science is mostly written retrospec tively, a generation or two after the actual events being discussed. Science historians are now analyzing and evaluating the origins of evolutionary and genetical theory in the nineteenth century and a sort of "Darwin industry" seems to have grown up. A history of mammalian cytogenetics by one of the main participants is, hence, a very welcome change, since it has a vividness, an immediacy and a personal flavor which these scholarly tomes and the official biog raphies of scientists mostly lack. The life of the author, Chinese-born, T. C. Hsu,...