ration: FIG. 481.--Theoretical development of the current
scroll.]

One secret of modification is found in the use of a radical in more than
one art, owing to differences in constructional characters. For example,
the tendency of nearly all woven fabrics is to encourage, even to
compel, the use of straight lines in the decorative designs applied.
Thus the attempt to employ curved lines would lead to stepped or broken
lines. The curvilinear scroll coming from some other art would be forced
by the constructional character of the fabric into square forms, and the
rectilinear meander or fret would result, as shown in. Fig. 482, _a_
being the plain form, painted, engraved, or in relief, and _b_ the same
idea developed in a woven fabric. Stone or brick-work would lead to like
results, Fig. 483; but the modification could as readily move in the
other direction. If an ornament originating in the constructional
character of a woven fabric, or remodeled by it, and hence rectilinear,
should be desired for a smooth structureless or featureless surface, the
difficulties of drawing the angular forms would lead to the delineation
of curved forms, and we would have exactly the reverse of the order
shown in Figs. 482 and 483. The two forms given in Fig. 484 actually
occur in one and the same design painted upon an ancient Pueblo vase.
The curved form is apparently the result of careless or hurried work,
the original angular form, having come from, a textile source.

[Illustration: _a_, free-hand form. _b_, form imposed, by fabric.
FIG. 482.--Forms of the same motive expressed in different arts.]

[Illustration: _a_, free-hand form. _b_, form imposed by masonry.
FIG. 483.--Forms of the same motive expressed in different arts.]

[Illustration: _a_ _b_ FIG. 484.--Variations resulting from change
of method.]

Many excellent examples illustrative of this tendency to modification
are found in Pueblo art. Much of the ornament applied to pottery is
derived from the sister art, basketry. In the latter art the forms of
decorative figures are geometric and symmetrical to the highest degree,
as I have frequently pointed out. The rays of a radiating ornament,
worked with the texture of a shallow basket, spring from the center and
take uniform directions toward the margin, as shown in Fig. 485. But
when a similar idea derived from basketry (as it could have no other
origin) is executed in color upon an earthen vessel, we observe a
tendency to de