In the title essay of this collection, all originally published in American Airlines' in-flight magazine, Asimov observes that size, dietary habits, and fecundity might be better gauges of a species' survival success than intelligence. (He cites rats and roaches as successful survivors.) Technology, not intelligence alone, has made homo sapiens successful; but it may also lead to its demise. Thus, the search for other civilizations is all the more urgentit may provide us with evidence that technology and survival need not be mutually exclusive. All the pieces here combine similarly humorous, intelligent, and imaginative observations on a wide-ranging set of topics, including DNA, irrigated agriculture, the English language, and robots. Asimov's 342nd book is enjoyable reading. Hilary D. Burton, Lawrence Livermore National Lab., Livermore, Cal.