This hypothetically chronological classification is, as has been said, due to Prof. Petrie, and has been adopted by Mr. Randall-Maclver and other students of prehistoric Egypt in their work.[3] To Prof. Petrie then is due the credit of systematizing the study of Egyptian prehistoric antiquities; but the further credit of having _discovered_ these antiquities themselves and settled their date belongs not to him but to the distinguished French archæologist, M. J. de Morgan, who was for several years director of the museum at Giza, and is now chief of the French archæological delegation in Persia, which has made of late years so many important discoveries. The proof of the prehistoric date of this class of antiquities was given, not by Prof. Petrie after his excavations at Dendera in 1897-8, but by M. de Morgan in his volume, _Recherches sur les Origines de l’Égypte: l’Âge de la Pierre et les Métaux_, published in 1895-6. In this book the true chronological position of the prehistoric antiquities was pointed out, and the existence of an Egyptian Stone Age finally decided. M. de Morgan’s work was based on careful study of the results of excavations carried on for several years by the Egyptian government in various parts of Egypt, in the course of which a large number of cemeteries of the primitive type had been discovered. It was soon evident to M. de Morgan that these primitive graves, with their unusual pottery and flint implements, could be nothing less than the tombs of the prehistoric Egyptians, the Egyptians of the Stone Age. [3] _El Amra and Abydos_, Egypt Exploration Fund, 1902.