Both the Greeks and the Romans dated the beginning of summer from the heliacal rising of the Pleiades and the beginning of winter from their heliacal setting.(1057) Pliny regarded the autumnal setting of the Pleiades as the proper season for sowing the corn, particularly the wheat and the barley, and he tells us that in Greece and Asia all the crops were sown at the setting of that constellation.(1058) (M273) So widespread over the world has been and is the association of the Pleiades with agriculture, especially with the sowing or planting of the crops. The reason for the association seems to be the coincidence of the rising or setting of the constellation with the commencement of the rainy season; since men must very soon have learned that the best, if not the only, season to sow and plant is the time of year when the newly-planted seeds or roots will be quickened by abundant showers. The same association of the Pleiades with rain seems sufficient to explain their importance even for savages who do not till the ground; for ignorant though such races are, they yet can hardly fail to observe that wild fruits grow more plentifully, and therefore that they themselves have more to eat after a heavy fall of rain than after a long drought. In point of fact we saw that some of the Australian aborigines, who are wholly ignorant of agriculture, look on the Pleiades as the givers of rain, and curse the constellation if its appearance is not followed by the expected showers.(1059) On the other side of the world, and at the opposite end of the scale of culture, the civilised Greeks similarly supposed that the autumnal setting of the Pleiades was the cause of the rains which followed it; and the astronomical writer Geminus thought it worth while to argue against the supposition, pointing out that the vicissitudes of the weather and of the seasons, though they may coincide with the risings and settings of the constellations, are not produced by them, the stars being too distant from the earth to exercise any appreciable influence on our atmosphere. Hence, he says, though the constellations serve as the signals, they must not be regarded as the causes, of atmospheric changes; and he aptly illustrates the distinction by a reference to beacon-fires, which are the signals, but not the causes, of war.(1060) FOOTNOTES M1 Death and resurrection of Oriental gods of vegetation. The Dying and Reviving god of vegetation in ancient Greece. M2 Dionysus, the god of the vine, originally a Thracian deity.