f the United States.

+SUGGESTIONS OF ACCIDENTS.+

Besides the suggestions of surface features impressed in manufacture or
intentionally copied as indicated above, we have also those of
accidental imprints of implements or of the fingers in manufacture. From
this source there are necessarily many suggestions of ornament, at first
of indented figures, but later, after long employment, extending to the
other modes of representation.

+IDEOGRAPHIC AND PICTORIAL SUBJECTS.+

Non-ideographic forms of ornament may originate in ideographic features,
mnemonic, demonstrative, or symbolic. Such significant figures are
borrowed by decorators from other branches of art. As time goes on they
lose their significance and are subsequently treated as purely
decorative elements. Subjects wholly pictorial in character, when such
come to be made, may also be used as simple decoration, and by long
processes of convention become geometric.

The exact amount of significance still attached to significant figures
after adoption into decoration cannot be determined except in cases of
actual identification by living peoples, and even when the signification
is known by the more learned individuals the decorator may be wholly
without knowledge of it.

MODIFICATION OF ORNAMENT.

There are comparatively few elementary ideas prominently and generally
employed in primitive decorative art. New ideas are acquired, as already
shown, all along the pathway of progress. None of these ideas retain a
uniform expression, however, as they are subject to modification by
environment just as are the forms of living organisms. A brief
classification of the causes of modification is given in the following
synopsis:

/Through material.
Modification of ornament------|Through form.
\Through, methods of realization.

_Through material._--It is evident at a glance that _material_ must have
a strong influence upon the forms assumed by the various decorative
motives, however derived. Thus stone, clay, wood, bone, and copper,
although they readily borrow from nature and from each other,
necessarily show different decorative results. Stone is massive and
takes form slowly and by peculiar processes. Clay is more versatile and
decoration may be scratched, incised, painted, or modeled in relief with
equal facility, while wood and metal engender details having characters
peculiar to themselve