The Naturalist

York (Fauna) juggles a plurality of naturalists in her cerebral, restrained, and intermittently affecting fourth novel. Darwinist ideas and classificatory scientific curiosity vie with deep-set propriety during a tropical upriver voyage. When an accident claims the life of Philadelphian Walter Ash in 1867, his headstrong young wife, a wealthy brewery heiress, decides she will honor Walter and undertake his planned specimen-collecting expedition to Brazil. She invites Rachel, her inquisitive assistant, and Paul, her buttoned-up stepson. Earnest if psychologically ill-equipped and loaded down with imperialist baggage, they soon face challenges to their self-assured civility. As their steamboat chugs toward Ilha das Tartarugas, these explorers suffer the oppressive weather and a jungle environment full of vampire bats, alligators, and nudity, all of which they regard as threatening or monstrous. Though hemmed in by decorum, they undergo subtle changes. The women trade their stifling clothing for trousers and begin to ponder the appeal of transgression. Paul, Brazilian-born and mixed-race, pores over his father's journal from an expedition 20 years earlier and gradually envisions a calling beyond the one expected of him. York's vivid descriptions stand out but cannot fully compensate for some character development getting short shrift and a meditation on Victorianism that would benefit from greater presence. Agent: Ellen Levine, Trident Media Group. (Apr.)