THE SUMMER HOUSES (278 pp.) —James Stevenson — Macmillan ($4.95).
Linked by an umbilical causeway to a shadowy mainland. Great Heron Island is the summer nesting place of a memorable colony of rare social birds. It swims in a body of water carefully left vague by the author but which readers will have no trouble at all locating — due south of O'Hara Point, due east of Marquand
Sound. On Great Heron, the great divide is not between rich and poor; there are no poor. It is the lingering schism from the great debate of 1942. when family was set against family over...