and to the concluding day, the _eng ebor olaba_, ‘the brightness of the moon’, but especially to the days of the dark half of the month, _en aimen_. The 16th is called _ol onjori_, ‘the greenish day’, the 17th, _ol onjugi_, ‘the red’, 18 to 20, _es sobiaïn_, 21 to 23, _nigeïn_, 27 etc., _en aimen nerok_, ‘the black darkness’. The people also emphasise the concluding days of the decades[716]. The natural foundation afforded by the phases of the moon therefore appears very clearly: the only noteworthy feature is that the days of the moon’s invisibility are included in the division which is called ‘the brightness of the moon’. An outside influence must no doubt be assumed. Among the Masai also the selection of lucky and unlucky days is common. The starting-points in the counting of the days of the month also afford evidence for the question as to which phases of the moon are the oldest, and were already utilised for this purpose. Both the methods of counting and the phases themselves are based upon a bisection or trisection of the month: to this were then added other phases, originally quite unsystematically. Among us the quarters of the moon are common; but of their use among primitive peoples I have found only a single instance. Of the Papuans of the Indian Archipelago it is stated that they divide the month into four parts according to the phases of the moon: _paik baleo_, the new moon, _paik jouwar_, the first quarter, _paik plejif_, the waning of the moon, and _paik imar_, the old moon[717]. It must not, of course, be taken for granted that these phases are of equal length, as ours are.