In The Bone People Keri Hulme uses the image of spirals frequently. As early as page seven readers encounter the architecture of Kerewin's tower, of which a spiral staircase is the center. The floor of Kerewin's home also contains an "engraved double-spiral, one of the kind that wound your eyes round and round into the centre where surprise you found the beginning of another spiral that led your eyes out again to the nothingness of the outside. . . . The spiral made a useful thought-focus, a mandala, anyway" (44). Kerewin later remembers that "it was reckoned that the old people found inspiration for the double spirals they carved so skilfully, in uncurling fernfronds: perhaps. But it was an old symbol of rebirth, and the outward-inward nature of things" (45). And Kerewin also puts spirals in her artwork: "a pattern of scrolls, but their coils become tangled and hectic so she screws them to oblivion" (74).
According to David Lewis (The Maori, London: Orbis Publishing, 1982), spirals are an old motif in Maori culture. The double spiral is in fact the most common of geometric forms in carving. It and at least forty-five other types of spirals appear, for example, in portrayals of heads of whales, on bows of war canoes, and in depictions of bird beaks. The prevalence of the spiral seems to have come, as Hulme writes, from the fernfrond, which holds a special significance in Maori life. Ferns and their trunks served many purposes, including food, objects of worship, and building materials. The curled coils of mariners' rope may also have inspired the spiral motif. Thus it is no wonder that spirals are a part of Maori culture and that they play so prominent a role in The Bone People.