The picture we have drawn of the high northern latitudes in early Tertiary times is vastly different. A great warm ocean occupied the Arctic regions, fed by three ocean currents analogous to the Gulf Drift, and the fall of temperature was gradual from the tropic to the pole. The return colder currents were mainly along the ocean floor and with little ice-formation the storms were few and not severe. On the western shores of the continents mild rain-bearing south-west winds prevailed, and a quiet moist warm atmosphere existed which was especially favourable to plant life. This favourable state of affairs lasted until well on in the Miocene, and then changes set in. The land and sea distribution underwent essential modifications. The great Tertiary continent or archipelago which is believed to have existed in the western Pacific, and whose last remaining summits now form the scattered islands of that ocean, gradually subsided, and in its place elevation began in higher latitudes. Bering Strait became narrow and shallow, and was probably for a time entirely closed, while the connexion between the Arctic and Indian Oceans was closed permanently, leaving in its lowest areas a chain of great inland seas and lakes, of which the Caspian and Aral Seas are now the greatest representatives. The Canadian Archipelago was probably raised above its present level, and formed a great northern extension of the American continental area. The changes in the Atlantic also were very extensive. The West Indies were the site of a large and lofty Antillean continent; further north a considerable land-mass existed east of Newfoundland; Greenland was joined on the west to the extended American continent, and considerably enlarged to the south-east. Iceland, though it remained an island, was elevated and probably nearly doubled in area, and between Iceland and the north of Scotland was developed a great submarine ridge, which may or may not have risen above the sea in places. The British Isles became a solid block of land, united with continental Europe across the English Channel and the great plain which is now the North Sea. Scandinavia was elevated by more than a thousand feet, and the elevation extended at least as far as Spitzbergen. The Murman area had a considerable extension. In eastern Asia the Sea of Okhotsk was land and Japan was united to the mainland.