differently, even among the same tribe, according to the preponderance of the decorative or descriptive value of the design.
On the other hand, the general prevalence of symbolic significance in ordinary decoration shows that this is an important aspect of decorative art, and a tendency to retain the realistic form might be expected, 
Fig. 3a. Ordinary Coat of the Gold of the Amur River. (After Dr. Berthold Laufer.) provided its origin were from realistic forms. If, therefore, the whole decorative art of some tribes shows no trace of realism, it may well be doubted whether their ordinary decorative designs were originally realistic.
The history of decorative design can best be investigated by analyzing the styles of form and interpretation prevailing over a limited area. If the style of art were entirely indigenous in a given tribe, and developed either from conventionalization of realistic designs or from the elaboration of technical motives, we should expect to find a different style and different motives in each tribe. The general customs and beliefs might be expected to determine the subjects chosen for decoration, or the ideas that are read into the technical designs.
As a matter of fact, the native art of North America shows a very different state of affairs. All over the Great Plains and in a large portion of the western plateaus an art is found which, notwithstanding local peculiarities, is of a uniform type. It is characterized by the application of colored triangles and quadrangles in both painting and embroidery in a manner which is found in no other part of the world. The slight differences of styles which occur are well exemplified in the style of painted rawhide bags or envelopes, the so-called 'parfleches.' Mr. St. Clair has observed that the Arapaho are in the habit of laying on the colors rather delicately, in areas of moderate size, and of following out a general arrangement of their motives in stripes; that the Shoshone, on the other hand, like large areas of
