Each glaciation of northern Europe must have been a time of greater rainfall as well as of lower temperature in the Mediterranean. The glacial anticyclone in the north displaced the storms from the Atlantic, which now mostly either skirt the north-west coast of Norway or pass across Denmark into the Baltic. These storms had to take a more southerly course, and entered the Mediterranean basin either across the south of France or in the neighbourhood of Gibraltar: tracks which are still occasionally followed in winter. These storms brought a rainfall much heavier than the present, and of a different character. The Mediterranean is now a “winter rain region,” and the north of Africa is entirely rainless for several months in the summer. But during the “Pluvial periods” it is probable that rain fell throughout the year, though the winter still had more than the summer. The winter rains were in the form of steady falls of long duration, such as we experience now in England, while the summer rains fell in short, heavy showers, perhaps accompanied by thunder. The Older Pluvial period, which corresponds to the Mindelian glaciation, had these conditions in their greatest development. Depressions cannot live long without a supply of moisture, either from the sea or from transpiring vegetation, and at present such winter storms as enter the Mediterranean are almost confined to its surface, and on the African side rarely penetrate more than one hundred miles inland. But at the period of greatest elevation the shrunken Mediterranean offered no such great attraction, and with a comparatively well-watered Sahara the storms were able to pass much further south. Consequently, northern Africa possessed a number of large and permanent rivers which reached the sea. It was along these rivers and their banks that the fauna still inhabiting the Saharan oases made its way, to be isolated there by the decrease of the rainfall, so that crocodiles and many species of fish now live in isolated pools and in rivers which lose themselves in the sand. In Egypt and Syria the first Pluvial period is double, corresponding to the Gunz and Mindel glaciations, with an intervening phase of feeble desert conditions, during which, however, the rainfall remained greater than the present. The second stage, corresponding to the Mindelian, indicates very great activity; at this time the Jordan Sea (Dead Sea) reached its greatest area, extending to the northern end of the Sea of Tiberias.