When the intercalary cycle was introduced from the East about the 7th century it did not come alone, but formed part of a mighty stream of civilisation which poured into Greece from the East at an early period. This is shewn e. g. in art, where all the styles formed under Oriental influence displace and transform the native geometrical style in vase-painting and the minor arts. Even in astronomy Oriental influence can be demonstrated. Astronomical science begins with Thales, who foretold the famous eclipse of the sun on May 28, 585 B. C. According to one isolated notice he also concerned himself with the lunisolar calendar. But the Ionian astronomy has a Babylonian foundation; evidences of this are the division of the day into 12 hours, and the signs of the zodiac, of which at least three can be shewn to be of Babylonian origin, and one is an Old Ionic transformation of a Babylonian original. But, it is said, the way from Ionia to the mother country is long, and the development of the mother country is in arrears. But even with Delphi the Ionians had early connexions; we may remember Croesus of Lydia. In the sixth century the eastern Greeks established splendid treasure-houses at Delphi, and long and intimate connexions must have preceded buildings of this nature. All the necessary conditions for the development assumed can therefore be demonstrated, as well as can be expected from the scanty nature of our sources for this period. The introduction of the cyclical regulation of the calendar has again introduced problems of far-reaching significance for scientific astronomy, though now upon a higher plane. The eight-year cycle was inaccurate, the problem was to find a more exact one, and how fruitful this problem became is shewn by such names as Meton and Kallippos. This difficulty prepared the way for the emancipation of the time-reckoning from the fetters of the religious cult. ADDENDUM TO P. 78 NOTE 2 (P. 80). Prof. Beckman has kindly pointed out to me that according to Are’s _Islendingabók_, ch. 7 (_þá vas þat mælt et næsta sumar áþr i lǫgum, at menn scyllde svá coma til alþinges, es X vicor være af sumre, en þangat til quómo vico fyrr_), the Althing in the year 999 A. D. was decreed for the time when ten (instead of nine) weeks of the summer had passed, i. e. it was postponed until a week later in the calendar. The reason for this is undoubtedly that the calendar (the week-year), and with it the Althing, had contrived to antedate itself a little more than a week in relation to the natural year, after Torsten Surt’s reform of the calendar had been introduced about the year 965. Here therefore we have an example of the empirical and occasional correction of the Icelandic calendar which was postulated above. LIST OF AUTHORITIES QUOTED. C.N.A.E., _Contributions to North American Ethnology_ (U. S. Geographical and Geological Survey of the Rocky Mountain Region). Washington, 1890--93.