With the ancient Pueblo peoples rectilinear forms of meander patterns were very much in favor and many earthen vessels are found in which bands of beautiful angular geometric figures occupy the peripheral zone, Fig. 480 _a_, but when the artist takes up a mug having a row of hemispherical nodes about the body, _b_, he finds it very difficult to apply his favorite forms and is almost compelled to run spiral curves about the nodes in order to secure a neat adjustment. [Illustration: FIG. 480.--Variations in a motive through the influence of form.] _Through methods of realisation_.--It will readily be seen that the forms assumed by a motive depend greatly upon the character of the mechanical devices employed. In the potter's art devices for holding and turning the vessel under manipulation produce peculiar results. In applying a given idea to clay much depends upon the method of executing it. It will take widely differing forms when executed by incising, by modeling, by painting, and by stamping. Intimately associated with methods of execution are peculiarities of construction, the two agencies working together in the processes of modification and development of ornament. I have previously shown how our favorite ornament, the scroll, in its disconnected form may have originated in the copying of natural forms or through the manipulation of coils of clay. I present here an example of its possible origin through the modification of forms derived from constructional features of basketry. An ornament known as the guilloche is found in many countries. The combination of lines resembles that of twisted or platted fillets of wood, cane, or rushes, as may be seen at a glance, Fig. 481 _a_. An incised ornament of this character, possibly derived from basketry by copying the twisted fillets or their impressions in the clay, is very common on the pottery of the mounds of the Mississippi Valley, and its variants form a most interesting study. In applying this to a vessel the careless artist does not properly connect the ends of the lines which pass beneath the intersecting fillets, and the parts become disconnected, _b_. In many cases the ends are turned in abruptly as seen in _c_, and only a slight further change is necessary to lead to the result, _d_, the running scroll with well-developed links. All of these steps may be observed in a single group of vessels.