The peopling of floral scrolls with living creatures is a decorative device which enjoyed unrivalled popularity throughout the whole history of Imperial art and in almost every country of the Empire. Its full cultivation and flowering were achieved in the Roman age; but its roots, like those of nearly every Roman art-motif, are in the late classical Greek and Hellenistic worlds. These roots were varied and complex. The primitive notion of spirits indwelling in trees and plants, and at a later stage personified in visible shape, may have played a part; some of the constituent elements can certainly be traced back to religious symbolism; and more immediate was the influence of the naturalistic trend of fourth-century art, which favoured the idea of rendering birds, insects, and small beasts in their native setting. In Hellenistic and Imperial times, as these elements mingled and the motif became more widespread, fancy came gradually to outweigh fact; and a delight in incongruity for its own sake found ready expression in the peopling of vine- and acanthus-rinceaux with mythological and genre scenes and figures, framed in the foliage or poised on slender stems, or with human figures and such solid quadrupeds as dogs, bulls, horses, bears, panthers, and lions, careering through the leafy whorls or springing from the hearts of flowers.