s; they occur as mere detached spots, to break the monotony of
spaces or lines; and in a thousand other ways give exercise to his
invention.

As a general rule, those leaves with serrated, or deeply cleft and
indented edges, lend themselves most readily to decorative treatment.
Large, broad leaves, with unbroken surfaces, and triangular or rounded
outlines, are less manageable. Those most commonly taken as models are:

_The Vine, with its Grapes._--This was freely used by medieval carvers,
at first for its symbolic significance, but afterward even more on
account of its rare beauty of form. The play of light and shade on its
vigorous foliage, the variety of its drawing in leaf, vine, and tendril,
and the contrast afforded by its bunches of oval fruit, caused it to be
accepted as a favorite subject for imitation in all kinds of carving. It
lends itself kindly to all sorts of relief, either high or low, in
almost any material. It is so recognizable, even in the rudest attempts
at imitation, that its popularity is well deserved.

The hop-vine shares some of these qualities, though much less strongly
marked in character.

_The Acanthus._--This leaf was first adapted for the purpose of ornament
by the workmen of classical Greece. The inspiration was one of the few
which they took directly from nature's models. It was also freely used
by medieval carvers, but with an insistence upon the flowing and
rounded character of its surface forms; and again by the Renaissance
artists, with a return to its classical character of fluted and formal
strength of line. The graceful drawing of its elaborately articulated
surface, and the extraordinary accentuation of its outline, provide an
endless source of suggestion. It has been adapted in all manners,
according to the fancy of the carver--sometimes long and drawn out, at
others wide and spreading. Altogether it has been more thoroughly
"generalized" than any other natural form.

_The Oak, with its Acorns_, appears in early medieval work, but without
much attempt to represent its form with anything like individual
character. In later work it has more justice done to its undoubted
merits as a decorative feature by a clearer recognition of its beauty in
clumps and masses. Fruit, other than the grape and a nondescript kind of
berry, was seldom represented by medieval craftsmen; it formed, however,
a marked feature in Renaissance ornament, where pomegranate, apple, fig,
and melon were in