Though not without a point of view -- the undesirability of overpopulation is an inescapable theme -- the authors neither lecture nor force conclusions; their approach might be described as responsibly Socratic, with almost as many questions in the 82-page text as declarative sentences (or so it seems until near the more overtly committed conclusion). The questions -- far from the simplistic, loaded or self-evident ones that characterize so many such introductions -- are skillfully designed to stimulate independent, disciplined inquiry. Topics (food resources, territoriality, aggregation, counting and sampling methods, and population density, turnover, controls, prediction, growth patterns and explosions) are introduced in such a way that reading the series of questions, directions and comments involves alert participation. The learning of course will be supplemented by more substance-oriented readings and reinforced by actually carrying out the suggested experiments. Though we can't imagine too many youngsters making age profiles for their communities and breeding fruitflies on their own, we can't think of a sounder springboard for a school unit or an adult-guided club or camp project on this timely and urgent subject.