Underappreciated as a novelist, Maxwell does little to enhance his reputation by collecting his short fiction, a volume of stories written over the past 50 years. The complete contents of the justly praised Billy Dyer (1991)- -related stories that resemble Maxwell's novels--are reproduced here. And the last quarter of the collection reprints what Maxwell himself calls ``improvisations,'' a series of fractured fables originally written to entertain his wife. These slight modern morality tales derive whatever complexity they have by juxtaposing archaic diction and contemporary concerns, but they're mostly too formulaic. An industrious tailor can't appreciate life in the present; a carpenter breaks his vow to keep secrets and shatters a town's serenity; in a land of immortals, the people begin to commit suicide. At two or three pages each, these provide Maxwell little room to flex his literary muscle. But even the stories from Maxwell's first collection of fiction--mostly about Upper East Side Manhattanites who live in fear of the city's darker corners and escape to country houses--aren't that impressive. The stories about French travel and its disappointments seem like cautionary tales for the sophisticated traveler. In ``A Game of Chess,'' Maxwell is particularly caustic about boorish Americans from the heartland who can't understand their bohemian relations in New York. The best stories, like Maxwell's novels, are nostalgic, recalling a genteel bourgeois life in downstate Illinois in the earlier decades of the century. ``What Every Boy Should Know'' beautifully captures the pangs of adolescence as an awkward boy copes with sex and a demanding father. Maxwell waxes poetic about a charming walk-up in Manhattan's Murray Hill in ``The Thistles of Sweden'' and sorrowfully rues the decline of New York in ``The Lily-White Boys,'' a sour tale of a Christmas Eve burglary. If you've already read Billy Dyer, there's little here worth exploring, especially if you haven't yet enjoyed Maxwell's wonderful novels.