of the Nile." It would indeed be difficult to discern where else they could have concentrated themselves. The dynastic history of ancient Egypt extends, at the lowest computation, over a period of more than three thousand years. In view of chronological difficulties, it has been found convenient to adopt the dynastic system of reckoning chosen by Manetho, an Egyptian priest who lived in the third century before Christ. Manetho divided the history of Egypt into thirty-one dynasties, of which some twenty-six comprise the period between Mena's Conquest and the Persian Conquest, while the others cover the period of Persian, Hellenic, and Latin supremacy. With the Persian Conquest, however, came the disintegration of the Egyptian Empire, and at that point purely native history comes to an end. Though Manetho's dynastic divisions have been adopted by modern Egyptologists, his chronology is not so well received, though it is supported by at least one distinguished authority--Professor Flinders Petrie. The general tendency at the present day is to accept the minimum chronology which is known as that of the Berlin School, which places Mena's Conquest at 3400 B.C. and the Twelfth Dynasty about 2000 B.C., rather than that of Professor Petrie, which would place these events at 5500 B.C. and 3400 B.C. respectively. It is customary to group the various dynasties into three periods--the Old Kingdom, comprising Dynasties I to VIII; the Middle Kingdom, Dynasties IX to XVIII; and the New Empire, Dynasties XVIII to XXVI. These divisions, however, do not imply any break in the course of Egyptian history, but are merely used for the sake of convenience. The following Table compares the systems of dating in vogue with students of Egyptian history, according to Professor Petrie and the Berlin School, as represented by Professor Breasted: PETRIE (1906) BERLIN SCHOOL (1906) B.C. B.C. I 5510 3400 II 5247 III 4945 2980 IV 4731 2900 V 4454 2750 VI 4206 2625 VII 4003 2475 VIII 3933 IX 3787 2445 X 3687 XI 3502 2160 XII 3459 2000 XIII 3246 1788 XIV 2793 XV 2533 XVI 2249 XVII 1731 XVIII 1580 1580 XIX 1322 1350 XX 1202 1200 XXI 1102 1090 XXII 958 945 XXIII 755 745 XXIV 721 718 XXV 715 712 XXVI 664 663 XXVII 525 525 XXVIII 405 XXIX 399 XXX 378 Egyptian Exploration