At a level where it's necessary to sketch in background basics on the origins of life and Mendelian genetics, Langone has perhaps bitten off more than his readers are equipped to chew. His broad survey ranges through such diverse and controversial topics as test-tube babies (which leads to artificial insemination, amniocentesis, embryo transfer); viruses, cancer, and aging; regeneration; recombinant DNA (will the yield be better crops or a Doomsday Bug?); prostheses; and mind modification (from electric brain stimulation and biofeedback to learning and memory transfer). To the extent that it's possible in such a crowded package, Langone provides admirably straightforward and understandable explanations of the procedures involved, and at almost every stage he urges readers to give serious consideration to the ""extremely complex and sensitive"" issues they raise. Regarding cloning, he wonders ""whether a future generation would gain anything from. . . a few extra copies of the Beatles or Buckminster Fuller""; and he quotes scientists who first isolated and synthesized E. coli genes but quake at the implications of their own accomplishments. His description, however, of such practices as shock treatment (""relatively safe""), lobotomy (""a last resort""), drugs for hyperkinetic children (no reservations), and aversion therapy (which ""changed Alex [in A Clockwork Orange] into a socially well-adjusted person"") seem unduly sanguine; and his parting words--there must be guidelines, but the guidelines must not be so restrictive as to stand in the way of science--are no help at all. Nevertheless, Langone gives readers much to think about; he explains difficult concepts with his usual intelligent clarity; and, needless to say, compared to Heintze's Genetic Engineering (1975), Langone's entry is a gem of concision and enlightenment.