Nature lovers! Here is an ""invitation to hone our sensitivity to the life forms immediately around us. . . . Through them we may see our sustaining life systems at work, and, above all, our own inextricable involvement with the biotic process."" Meet the bullthistle, a stream, some spring ephemerals and winter birds, a deadwood community, a host of caterpillars and the ecosystem of a country house where snakes, spiders, bats and mantises have come to stay.