In the accompanying engraving from a sarcophagus in the Lateran, of the fourth or fifth century, the lamb, wearing the nimbus in which are inscribed the sacred monogram and the letters Alpha and Omega, the emblems of divinity, is standing upon a hillock, perhaps intended for 250 Mount Zion,[400] from which flow four streams, probably the “river of water of life,... proceeding out of the throne of God and of the Lamb,” and dividing toward the four quarters of the earth. These streams are also variously interpreted as signifying the four evangelists, and the four rivers of paradise.[401] On a sarcophagus of later date Our Lord is represented in human form with a scroll in his hand, standing on a mound from which the four mystical rivers flow, and by his side a lamb bearing a Latin cross on its head. On either side are lambs, personifications of the apostles, to whom he is giving the final commission to preach in all lands the gospel contained in the scroll which he holds, and to baptize with the sacred waters at their feet. Sometimes twelve lambs are represented approaching one in the centre, as in frescoes in St. Clement’s at Rome, and at Ravenna. On a gilt glass patera in the Vatican Library the lambs are seen to issue from Jerusalem and Bethlehem, as indicated by their names written above, and to approach Mount Zion, from which flow the four evangelical streams united in the mystical Jordan. This is perhaps emblematic of the twelve tribes, or of the gentiles coming from the east and west to drink of the water of life. Paulinus describes a mosaic in his basilica of Fondi, where a cross symbolical of Christ 251 was placed on the rock, and two flocks, of sheep and goats respectively, stood around it. “The shepherd turns away,” he says, “the goats on the left, and embraces with his right hand the well-deserving lambs.”[402] This was perhaps the first of that series of art-presentations of the last judgment which culminates in the tragic terrors of the Sistine Chapel. Sometimes a milk-pail is represented near a lamb, or hanging on a crook by its side, or even resting on its back. Sometimes also it is carried by the Good Shepherd. This has been magnified without due evidence into a symbol of the eucharist. It might more naturally be regarded as an emblem of the blessings of salvation, set forth by Isaiah under the figure of wine and milk, or it may refer to the soul’s being fed with the sincere milk of the word.