The co-author of The Monkey Puzzle (p. 917) combines a canny scientific understanding with adroit expository skills in an ambitious, sometimes daunting review of where we are in genetic engineering: history, successes, potential, prospects for good or evil. Anyone but an avid student will have to read and read again large sections that explain exactly how you cut and hybridize DNA, zip it into an appropriate vector, infect your enfeebled strain of bacteria E. coli (or some other useful bug), and see what you harvest. Few popular works, however, supply the nitty-gritty. And there's much more to the volume than recipes. Cherfas provides synopses of the initial experiments, the Watson-Crick work, and the technical advances of such as Paul Berg, David Baltimore, and Walter Gilbert in recent years--conveying the beauty of the ideas and the imagination of the innovators. His account of genetic engineering as a venture capital and growth industry reveals that we have yet to reap commercial benefit from human insulin, types of interferon, and other glittering promises. (But the benefits are real, he avers, and may be around the corner.) On the other hand, insulin and other hormones may be harvested directly from bacteria, bypassing the whole gene-splicing business--for it turns out that some bacteria and other lowly creatures naturally make the hormones for reasons not yet understood! In his later chapters Cherfas details the history of the leading companies, as well as the still unresolved problems over patents, academic freedom, and conflict of interest. He even adds the specter of diabolic warfare in which madmen could wipe out the enemy with engineered pathogens while protecting the local masses with appropriate vaccines. It's all here, well-thought and well-wrought, but requiring a comparably thoughtful and patient reader.