The bas-reliefs, however, by no means form the chief attraction of this pulpit. At each of its six angles stand saints, evangelists, and angels, whose symbolism it is not now so easy to decipher. The most beautiful groups are a company of angels blowing the judgment trumpets, and a winged youth standing above a winged lion and bull. These groups separate the several compartments of the bas-reliefs, and help to form the body of the pulpit. Beneath, on capital's of the supporting pillars, stand the Sibyls, each with her attendant genius, while prophets lean or crouch within the spandrils of the arches. Thus every portion of this master-work is crowded with figures--some detached, some executed in relief; and yet, amid so great a multitude, the eye is not confused; the total effect is nowhere dissipated. The whole seems governed by one constructive thought, projected as a perfect unity of composition.[63] A later work of Giovanni Pisano was the pulpit executed for the cathedral of Pisa, now unfortunately broken up. An interesting fragment, one of the supporting columns of the octagon which formed the body of this structure, still exists in the museum of the Campo Santo. It is an allegorical statue of Pisa. The Ghibelline city is personified as a crowned woman, suckling children at her breast, and standing on a pedestal supported by the eagle of the Empire. She wears a girdle of rope seven times knotted, to betoken the rule of Pisa over seven subject islands. At the four corners of her throne stand the four human virtues, Prudence, Temperance, Justice, and Fortitude, distinguished less by beauty of shape than by determined energy of symbolism. Temperance is a naked woman, with hair twisted in the knots and curls of a Greek Aphrodite. Justice is old and wrinkled, clothed with massive drapery, and holding in her hand the scales. Throughout this group there is no attempt to realise forms pleasing to the eye; the sculptor has aimed at suggesting to the mind as many points of intellectual significance as possible. In spite of ugliness and hardness, the "Allegory of Pisa" commands respect by vigour of conception, and rivets attention by force of execution.