Mahlon Hoagland tells the DNA story with the same style and zest he exhibited in his earlier popularization, The Roots of Life (1978). The molecular biologist spins out the story from Mendel, Morgan, and Muller down to the crucial events of the 1940s and '50s and such laureates as Watson, Crick, Luria, Ochoa, Lederberg, and Nirenberg. Hoagland's skills come to the fore in his use of good metaphors and in his explanations of the logic behind the design of many ingenious experiments. He also shows how the landmark discoveries of the period led to the coming together of the scientists studying the viruses that infect bacteria--the ""phage"" group""--with biochemists, biophysicists, and others into what is now called molecular biology. Hoagland himself (working with Paul Zamecnik) played a major role in describing the mechanism of protein synthesis in cells via the discovery of transfer RNAs: the small molecules that pick up amino acids for incorporation into proteins. Throughout Hoagland's tale--and it is a tale with suspense and excitement--runs the intuitive mind of Francis Crick, always at or near the center of creative ideas. (Crick had independently hypothesized the existence of transfer RNAs--he called them adaptor RNAs--before their discovery.) In Hoagland's account there are no villains. Erwin Chargaff's bitterness is noted, as is Watson's brashness and the unpleasantness over Rosalind Franklin. The rivalry is there; but Hoagland is more concerned, now, with providing a coherent picture of how the great revolution in biology occurred, and how the central dogma--that information flows from DNA to RNA to proteins--was established. A rich and rewarding landscape--and not so detailed as to overwhelm the general reader.