The evidence of any racial connection between the earliest known inhabitants of the two countries is very precarious; as regards their art, their customs and their language, the Sumerians on the one hand, and the pre-dynastic and early dynastic Egyptians on the other, show a complete independence of each other; both countries were probably invaded at an early period of their histories by the Semites, who in the case of Mesopotamia completely supplanted their predecessors of different stock, but who were at the same time themselves absorbed by the higher civilization of the Sumerians to which they were the destined heirs, and to the further development of which they themselves were to contribute so largely; but at what period or periods the Semites swept over Egypt and the north coast of Africa, impressing their indelible and unmistakable stamp upon the foundation-structure of the Egyptian and Libyan languages is not known; whenever it was, we can safely assume that their advent took place in prehistoric days, for the hieroglyphs and probably also the language of the dynastic Egyptians were the natural development of the language and crude picture-signs of their predecessors, and the theory of a violent break in the continuity of early Egyptian civilization at the commencement of the first dynasty is daily becoming more untenable. We are similarly unable to assign any definite date to the arrival of the Semites in the Mesopotamian Valley, though the Neo-Babylonian King Nabonidus gives us a traditional date for Shar-Gâni-sharri[3] (Sargon) and his son Narâm-Sin, kings of Agade, who, so far as we know, established the first Semitic empire in the country. There were indeed Semitic Kings of Kish before the time of Shar-Gâni-sharri, but the extent of their sway was clearly very limited compared with the far-reaching empire of the rulers of Agade. But there are reasons for doubting the accuracy of the traditional date of 3750 B.C. which Nabonidus assigns to Narâm-Sin, the chief reason being the extraordinary gap in the yieldings of Babylonian excavations between the time of Shar-Gâni-sharri and Narâm-Sin, and that of Gudea, the priest-king of Lagash in Southern Babylonia, who reigned about 2400 B.C.; that is to say, concerning a period of about 1300 years the excavations have afforded us practically no information whatever, while both at the beginning and at the close of that period, we have abundant evidence of the civilization and history of the inhabitants of Babylonia; secondly, the style of art characteristic of the time of Gudea and the kings of Ur, as also the style of writing found in their inscriptions, presuppose no such long interval between the time of Sargon and their own day. But there are yet other considerations which are even more potent, and which deserve greater attention than has been up to the present accorded to them, depending as they do upon the stratification of the ruined mounds themselves. Now it is a very