Practically all the spirals in primitive art are equidistant. It can easily be shown that spirals develop in many different ways. As has been pointed out by Semper, the coiling of wire or the making of coiled basketry or pottery must lead to the discovery of the ornamental spiral. Wrapping with twine may have a similar result. In other cases the spiral develops without technical motives from natural forms. This is exemplified, for instance, by the spirals used for expressing the nostrils of the beaver, bear and dragon-fly in northwest coast art (see figs. 157 p. 186, 175 p. 193). It is, however, doubtful whether the spiral has ever become in this manner a dominant motive of local art. [Illustration: Fig. 137. Types of New Zealand spirals.] The New Zealand carved spiral (fig. 137) is generally double; one arm running in, the other out, and the two clasping each other in the center. The spirals are so placed that their general contours harmonize with the decorative field, although their outer turns often cut into its borders. The appearance of the spiral is strongly influenced by the application of a common pattern of carving, which consists of a long lineal field with crosshatching limited by two or more equidistant lines. The two arms of the spiral are connected at regular intervals by small bars having crossline decoration. In other cases the spirals themselves are decorated with crosslines, while the surrounding lines are smooth. Sometimes the spirals are given a notched outline. Single spirals consisting of a number of equidistant lines, occur in tattooing and in wood carving representing tattooed faces. Spirals are often connected and form S shaped figures and when placed serially in a narrow field, they are accompanied by a series of equidistant lines,—fragments of the outer turns that would have shown if the spiral had been able to develop freely. The spiral of eastern New Guinea is in some ways similar to the one of New Zealand. The double spiral appears commonly in both areas, also the notches or scallops on the spiral and the filling in of the gore with curved lines accompanying the outer turns of the spiral (fig. 138). The lack of connecting bars, of the crossline decoration and the fundamentally different design arrangement, as well as the treatment in black and white differentiate the New Guinea spiral from that of New Zealand. The curves are fitted much more rigorously in the decorative field. The great freedom of the New Zealand forms, the delicate accuracy of all the constituent elements, and the multiplicity of forms connected with the spiral, are absent.