The "Adoration of the Lamb" is dominated in the upper zone by a triple panel, the centre framing the Almighty enthroned in majesty, whose is the kingdom, the power, and the glory--a supreme conception of the Eternal Father, unequalled for majestic stillness of face, intellectual power of brow, and depth and placidity of vision; on His right is the Mother of Christ, testifying to the full the lowliness of the handmaiden of the Lord, on His left St. John the Baptist, an earnest type, long of hair and rugged of beard, barefooted, and in a raiment of brown camel's hair girdled about the loins, intensifying the austerity of life ordained for him who was to prepare the way of the Lord and make straight His paths. In the "Choir of Angels" (Plate II.), which is the subject of the first lateral panel in the dexter shutter, we have one of the choicest gems of the polyptych, and it affords us a measure of the distance the realistic tendencies of the painter had carried him from the traditions of the mystic school. Justified by the warrant of Scripture, he translates these spirit beings into purely human frames, but with a nerve system attuned to material sensations. In these angels there is no suggestion of trance-like ecstasy in contemplation of the Beatific Vision; they are angels materialised whose features reflect the strain of sustained effort and the underlying sense of pain which in man is inseparable from the sensing of intense joy. Evidently the master had fathomed the secrets of the human heart: the sense possibilities of the spirit world were without his ken, so he humanised his angels and evolved types understandable of the people, and at the same time one of the finest angel groups of all art. So inexpressibly realistic are his conceptions that to the poet-biographer Van Mander, at any rate, it was actually possible to discern "the different key in which the voice of each is pitched." But poets are privileged beings. Accompanying the Choir in their song of praise with organ, harp, and viol are the balancing group of angels in the corresponding compartment of the sinister shutter, types that, strangely enough, are in striking contrast to the former, their features moulded in placid contentment. The extreme panels of this zone are occupied by life-size presentations of our First Parents after the Fall, nude figures painted from the life, with absolute fidelity to nature and masterly conception of type: in a demi-lunette over the figure of Adam we see Cain and Abel making their offerings unto the Lord, and in that over Eve the slaying of Abel at the hands of his brother. There is a tradition extant that the altar-piece was originally furnished with a predella painted in distemper, a picture probably of Limbo or of Purgatory, but no trace of this remains. [Illustration: PLATE IV.--PORTRAIT OF THE PAINTER'S FATHER-IN-LAW (By John van Eyck)