Recent archaeological research thus leaves small room for the theory that Egyptian culture was subjected to any strong foreign influence in early dynastic times, and its conclusions on this point are confirmed by anatomical evidence. The systematic measurement and comparison of skulls from predynastic and dynastic burials, which have been conducted by Dr. Elliot Smith of the Khedivial School of Medicine in collaboration with the Hearst Expedition, has demonstrated the lineal descent of the dynastic from the predynastic Egyptians. The two groups to all intents and purposes represent the same people, and in the later period there is no trace of any new racial element, or of the admixture of any foreign strain. Thus the theory of an invasion of Egypt by Semitic tribes towards the close of the predynastic period must be given up, and, although this does not in itself negative the possibility of Sumerian influence having reached Egypt through channels of commercial intercourse, it necessitates a more careful scrutiny of the different points of resemblance between the cultures of the two countries on which the original theory was founded. One of the subjects on which the extreme upholders of the theory have insisted concerns the invention of the Egyptian system of writing, which is alleged by them to have been borrowed from Babylonia. But it must be noted that those signs which correspond to one another in the two systems are such as would naturally be identical in any two systems of pictorial writing, developed independently but under similar conditions. The sun all the world over would be represented by a circle, a mountain by a rough outline of a mountain peak, an ox by a horned head, and so on. To prove any connection between the two systems a resemblance should be established between the more conventionalized signs, and here the comparison breaks down completely. It should further be noted that the Egyptian system has reached us in a far more primitive state than that of Babylonia. While the hieroglyphic signs are actual pictures of the objects represented, even the earliest line-characters of Sumer are so conventionalized that their original form would scarcely have been recognized, had not their meaning been already known. In fact, no example of Sumerian writing has yet been recovered which could have furnished a pattern for the Egyptian scribe.