With peoples who did not live too far from the equator, the Moon, therefore, took precedence of the Sun. Among the Mexicans existed, long ago, a peculiar unit for measuring long periods of time, called “_tonalamatl_,” comprising 260 days. It was undoubtedly intended to contain nine synodical months (reckoned from new Moon to new Moon). But such a period would consist of 265.58 days and so could not be made to agree with the double decade and was therefore shortened to 260 days, as we round off the solar year, in reality 365.24 days, to an even 365 days. Elaborate studies have been made in order to explain why the Mexicans chose nine synodical months instead of twelve, as most other peoples, but the question has not been solved. This much is certain, that “_tonalamatl_” has nothing to do with the solar year, but only with the month. The high age of “_tonalamatl_” is proved by the fact that the priests adhered to it in magic and horoscope casting long after the solar year came into public use. A learned Mexican, de Jonghe, has pointed out that “_tonalamatl_” was used by all the tribes belonging to the Nahua-group, which tribes separated very long ago. This unit of time, therefore, bears all the evidence of a very high age, but is obviously younger than the synodical month. Our information in regard to Moon-worship among the peoples of Mesopotamia is even more explicit. The Moon (Sin) was rendered homage far earlier than the Sun (Shamash). The following translation of a hymn in cuneiform letters I quote from L. Bergström, who published a study on “Semitic Moon-Worship” in _Nordisk Tidskrift_, 1909: Oh, Sin, thou who alone givest light, Thou, who bringest light to men, Thou, who showest favour to the dark-tressed ones, Thy light shines on the firmament, Thy torch illuminates like fire, Thy radiance fills the wide earth. Oh, heavenly Anu, whose insight and wisdom no one comprehends, Thy light is splendid as Shamash, thy firstborn, Before thee prostrate the great gods themselves in the dust For on thee rests the fate of the world.