THE LOST UPLAND

 Poet Merwin's long familiarity with rural southwestern France provides him with his subject here--for three slow, vagrant, and accomplished prose portraits. The first, ``Foie Gras,'' concerns a nobleman, the Comte d'Allers, known otherwise as Fatty, who's been down on his luck long enough to have developed a system for cadging, shoplifting, and deadbeating that has become the fabric of local legend. The second piece, ``Shepherds,'' is the most personal and the best: the pace of life and knowledge in the Languedoc, the mystery of one's neighbors, the feel of the land, the crops, the animals. ``Blackbird'' seems the most conventionally like fiction- -the portrait of an aging wine-dealer who's looking for someone to take over his business; Merwin here most memorably reproduces the laconic courtesy and pointedness of local speech. All three pieces require patience from the reader, and the rewards are less narrative than stylistic: Merwin remains the finest prose writer of American poets, with a special talent for describing the spatial: ``As we stood looking at it, to the east, the tracks out of sight below us began to ring faintly in our ears, and then the train appeared around a rise in the causse that did not look like anything at all but clearly the rest of the world was back there.''