On a whim, Charlene Gourguechon left her PR job at New York's Lincoln Center and joined a French film crew on an expedition to the New Hebrides, those dots in the Pacific that globe-trotters pass en route to New Caledonia or Fiji. Her account of that 1970 excursion is an unfailingly colorful mix of tribal data and personal reaction. The Melanesians they visited (generally labeled Big Nambas and Small Nambas, depending on the size of their penis sheaths) show evidence of the same 20th-century encroachments that Margaret Mead has so ably documented elsewhere: in one village, everything was either taboo or for sale. Local chieftains are a varied lot, ranging from fierce guardians of tradition--no cameras or ladies allowed--to shrewd entrepreneurs, equally comfortable with backcountry pig exchanges or European currencies. Cannibalism is fading and missionaries have established schools but the yam diet remains as do traditional arts and original systems of justice: the Mbotogote make judicial decisions according to knuckle-cracking sounds. Gourguechon, who married the cameraman early on, is kinder to the tribesmen and their transparent motives than to the British and French washouts back in town--an old-movie cast of beachcombers, missionaries, and untaxed business people who drink too much, missionize fecklessly, and show an almost uniform contempt for the natives. Generously laced with pidgin words, this is an engrossing, briskly paced narrative of local customs, ongoing rivalries, and regular bouts with malaria.