Moons are more obvious measures of time than suns, in the tropics at least--probably everywhere; for the waxing and waning of the moon mean much to people who live largely out of doors; and the month is, perhaps, the earliest fixed mode of reckoning time beyond a day or two. Most savages count time mainly by so many moons. But they must also have noticed early that after a certain number of moons (usually about thirteen), certain fruits or seeds were ripe again; especially must they have noticed it when this recurrence coincided with the return of the rainy season, or of some other annual meteorological phenomenon, like the bursting of the monsoon or the Nile inundation. Thus, even in the tropics, and before the coming on of the Glacial epoch, men or the ancestors of men (one can not draw precise lines here) must probably have observed a certain rough relation between the months and the vegetative cycles; after so many moons, about say thirteen, the yam, or the mangoes, or the grains are ripe again. These organic years, I take it, must have been noticed before the astronomical ones. For it is now beginning to be more and more believed that man is of preglacial origin; and even if something worth calling a man were not, then at least man's pre-human ancestors go back far into the Tertiary period. Only later would men begin to note that some thirteen moons, and the recurrence of a food stuff, concurred with a particular solar season. Indeed, if one comes to think of it, how much even now do any of us, save the most scientific, mean by the year, beyond the visible change of summer and winter? What we are thinking of is the leafless trees, the ice and snow, the green grass in spring, the flowers and warm days in summer, not the abstract astronomical fact of the earth's revolution round the sun, or the due succession of the signs of the zodiac. It is that visible organic year that must have counted most with man from the first; though no doubt its meaning and reality are much more vividly present since the coming on of the Glacial epoch, and the more so in proportion as we live nearer to the north or south pole; while at the equator the year is to the last a much more inconspicuous period--a largely artificial mode of reckoning.