"The rule is so stern, that all delight in mere incidental beauty, which painting often triumphs in, is wholly forbidden to sculpture; -- for instance, in _painting_ the branch of a tree, you may rightly represent and enjoy the lichens and moss on it, but a sculptor must not touch one of them: they are inessential to the tree's life, -- he must give the flow and bending of the branch only, else he does not enough 'see Pallas' in it."