The disappearance of all trace of the regulators is felt by some to be a difficulty in the way of the admission of their former existence, inasmuch as the ancients built on such a colossal scale. But the Labyrinth, which was built out of the reach of water, has disappeared, and its traces were only of late years identified in a mass of stone chips and trenches filled with sand, which underlay the foundations. Such being the fate of the Labyrinth, which must have surpassed the regulators as a structure of colossal dimensions, it is only natural to suppose that the stones forming the superstructure of the regulators should also have been removed for the same objects as the stones of the Labyrinth, and, if the materials of the floors were spared, it would only be on account of their situation being unfavourable to their removal. But, if spared, the action of running water would in time cause their disappearance, either by undermining them and burying them to depths below their original position, or by depositing a layer of mud above them. In the latter case they may still exist in a situation where some future excavation may chance to bring them to light again. Hence I hold that, in the face of Strabo’s explicit statement that there were regulators at each end of the canal for controlling the inflow and outflow of the lake, the objection of want of evidence of the former existence of regulators is not sufficiently strong to be allowed to have much weight against the theory, that the submerged Fayûm, with the entry and exit of its waters kept under control by regulators, and its water-levels ranging between R.L. 22·50 and 19·50, was the Lake Mœris of Herodotus; the Arsinoïte Nome, in connection with it, consisting of the reclaimed high lands within the limits of the lake and along the borders of the lake itself and margins of the feeder canal. It is admitted, as a weak point in this theory, that unless the Arsinoïte Nome can be imagined as extending into the Nile Valley, the area of cultivable land comprised in the nome is very limited. Let us see how far such a conception of Lake Mœris is in accord with the testimony of the ancient records which relate to it.