The hero of Heinrich Boll's last novel, The Clown, was an artistic loner who manfully rejected the cosy isms of a de-Nazified Germany. A similarly put-upon individualist held the center of the stage in Billiards at Half-past Nine. Both of these sad, sinewy, sardonic creations conveyed a sharp sense of recent European history, the litter pile of war and its harsh, bumbling aftermath. With Boll's current collection of eighteen tales, variations on the familiar themes once again are heard though largely drained of energy and technically somewhat slack. Greed, guilt, pettiness, frustration, the mechanics of survival, the quiet despair or marginal joys of family life are the principal concerns, obliquely etched against political, social, or religious backdrops. Some seem little more than sketches; others play with the fable or diary as in Kafka; a few are excursions into childhood nostalgia and frightful awakenings. ""The Adventure"" ironically mixes the Catholic confessional and adultery; a surrealist fancy about circus animals quartered in a bourgeois home is funny, if inexplicable; ""The Post Card"" offers a slight, moving glimpse of an only son's induction the summer before the War; and ""In the Valley of the Thundering Hooves,"" the meatiest specimen, is a grimly poetic unveiling of adolescent sex and brutalized innocence. Throughout one senses Boll's underlying comments on the difficulties or inanities of modern living, past and present, but the tone has a subdued mocking edge, a little too detached, like the benumbed pain of a patient.