The chancel wall one day sounded hollow when struck; the mortar was removed, and underneath there appeared an arched aperture, which had been filled up with jumbled carved work and a crushed drain. It was cleared out, and so rebuilt as to occupy the exact site of its former existence. It is of the very earliest type of Christian architecture, and, for aught we know, it may be the oldest piscina in all the land. At all events, it can scarcely have seen less than a thousand years. It perpetuates the original form of this appanage of the chancel; for the horn of the Hebrew altar,[14] as is well known to architectural students, was in shape and in usage the primary type of the Christian piscina. These horns were four, one at each corner, and in outline like the crest of a dwarf pillar, with a cup-shaped mouth and a grooved throat, to receive and to carry down the superfluous blood and water of the sacrifices into a cistern or channel underneath. Hence was derived the ecclesiastical custom that, whenever the chalice or other vessel had been rinsed, the water was reverently poured into the piscina, which was usually built into a carved niche of the southward chancel wall. Such is the remarkable relic of former times which still exists in Morwenstow church, verifying, by the unique and remote antiquity of its pillared form, its own primeval origin. [Illustration: THE PISCINA IN MORWENSTOW CHURCH _From a photo by S. Thorn, Bude_] But among the features of this sanctuary none exceed in singular and eloquent symbolism the bosses of the chancel roof. Every one of these is a doctrine or a discipline engraven in the wood by some Bezaleel or Aholiab of early Christian days. Among these the Norman rose and the _fleur-de-lis_ have frequent pre-eminence. The one, from the rose of Sharon downward, is the pictured type of our Lord; the other, whether as the lotus of the Nile or the lily of the vale, is the type of His Virgin Mother; and both of these floral decorations were employed as ecclesiastical emblems centuries before they were assumed into the shields of Normandy or England. Another is the double-necked eagle, the bird of the Holy Ghost in the patriarchal and Mosaic periods of revelation, just as the dove afterwards became in the days of the Gospel; and, mythic writers having asserted that when Elisha sought and obtained from his master “a double portion of Elijah’s spirit,” this miracle was portrayed and perpetuated in architectural symbolism by the two necks of the eagle of Elisha. Four faces cluster on another boss,--three with masculine features, and one with the softer impress of a female countenance, a typical assemblage of the Trinity and the Mother of God. Again we mark the tracery of that “piety of the birds,” as devout writers have named the fabled usage of the pelican.[15] She is shown baring and rending her own veins to nourish with her blood her thirsty offspring,--a group which so graphically interprets itself to