The observances in question, or rather broken fragments of them, have now attached themselves to a number of different outstanding dates in the Christian calendar, and the reconstruction of the original year, with its seasonal feasts, is a matter of some difficulty[371]. The earliest year that can be traced amongst the Aryan-speaking peoples was a bipartite one, made up of only two seasons, winter and summer. For some reason that eludes research, winter preceded summer, just as night, in the primitive reckoning, preceded day. The divisions seem to have been determined by the conditions of a pastoral existence passed in the regularly recurring seasons of central Europe. Winter began when snow blocked the pastures and the cattle had to be brought home to the stall: summer when the grass grew green again and there was once more fodder in the open. Approximately these dates would correspond to mid-November and mid-March[372]. Actually, in the absence of a calendar, they would vary a little from year to year and would perhaps depend on some significant annual event, such as the first snowstorm in the one case[373], in the other the appearance of the first violet, butterfly or cockchafer, or of one of those migratory birds which still in popular belief bring good fortune and the summer, the swallow, cuckoo or stork[374]. Both dates would give occasion for religious ceremonies, together with the natural accompaniment of feasting and revel. More especially would this be the case at mid-November, when a great slaughtering of cattle was rendered economically necessary by the difficulty of stall-feeding the whole herd throughout the winter. Presently, however, new conditions established themselves. Agriculture grew in importance, and the crops rather than the cattle became the central interest of the village life. Fresh feasts sprang up side by side with the primitive ones, one at the beginning of ploughing about mid-February, another at the end of harvest, about mid-September. At the same time the increased supply of dry fodder tended to drive the annual slaughtering farther on into the winter. More or less contemporaneously with these processes, the old bipartite year was changed into a tripartite one by the growth of yet another new feast during that dangerous period when the due succession of rain and sun for the crops becomes a matter of the greatest moment to the farmer. Early summer, or spring, was thus set apart from late summer, or summer proper[375]. This development also may be traced to the influence of agriculture, whose interest runs in a curve, while that of herding keeps comparatively a straight course. But as too much sun or too much wet not only spoils the crops but brings a murrain on the cattle, the herdsmen fell into line and took their share in the high summer rites. At first, no doubt, this last feast was a sporadic affair, held for propitiation of the unfavourable fertilization spirits when the elders