Next followed the final readvance of the ice forming the great “Baltic” moraines which fringe the Baltic coast of Germany, turning northward in the west into Denmark and in the east into Finland. There was a corresponding re-development of glaciers in the Alps (Bühl stage) and in the mountains of Ireland and Scotland, though these probably failed to reach the sea even in Scotland. This period gave us a repetition of the climate of the preceding maxima. In this case we have definite evidence of the presence of a belt of easterly winds on the southern side of the ice-sheet, in a series of “barkans” or fossil dunes in Holland, Germany and Galicia. These dunes were formed of fine ice-deposited material, and they are crescent-shaped, with their convexities to the east, indicating that they were built by strong easterly winds. A moment’s consideration will show the truth of the latter statement. Suppose there is an isolated round hillock of sand exposed to strong easterly winds. The sand grains will travel up the easterly windward slope of the hillock and roll down the westerly leeward side. In this way the whole hillock will advance very slowly westwards. But in the centre, where the hillock reaches its greatest height, the grains will take longer to reach the highest point than near the edges, where they have not to rise so high. At the edges a strong gust will carry some of the heavier grains right over the dune, while nearer the centre they will be left half-way, and when the gust ceases will perhaps roll back to their original position. In this way the margins of the dune will advance westward more rapidly than the centre, producing the crescent shape with the convex side to the east. At the time of their formation these dunes must have had their steepest side to the westward, but the westerly winds which have prevailed during the last few thousand years have succeeded in modifying that detail, without destroying the general shape of the dunes, and the steepest slopes are now on the eastern side. The preservation of the original shape, in spite of the subsequent development of westerly winds, is due in part to the coating of vegetation, which protected the dunes as soon as more favourable conditions occurred, and probably in part to the lesser velocity of the westerlies. If the period of east winds and dune formation had been long enough, we might have had another deposit of loess, but it was short, and vegetation, which is necessary to the genesis of true loess, had no time to establish itself before the climate changed again with the final retreat of the ice. The climate of this period in Rumania has been ably described by G. Murgoci: “In general the prevailing climate of the time of the formation of loessoid soils and blown sands must have been that which is named by E. de Martonne the aralian climate, a dry climate with some rain in spring to call forth a poor and transient vegetation and to maintain the flowing water in rivers and lakes.