The wild horses were evolving three utterly different types. On the chalk downs, and on the limestone tracts north of the Humber, there were lightly built, slender, graceful horses of fair height. On the clays there were {44} horses, heavy, coarse, and slow. On the Breton, British and Scandinavian moors there were Celtic ponies. [Sidenote: The deluge in Cloudland] It needed but little sinking of this land to flood the Delta, and open a long channel up the North River valley. The sea washed out the clay foundations of the forests. The sea breakers wielded boulders of the glacier-drift and hurled them like battering rams against the dissolving limestone of low cliffs. The tide swung gravels to tear out bays in the foreshores. Winter frosts cracked the headlands, and summer rains melted the ice cracks so that the capes fell into the sea in landslides. Thus the sea widened, biting its way deep into Europe until men began their losing fight with dykes for the saving of doomed netherlands. The North Sea cut its way through chalk downs into the English channel. The tribes who held fortified headlands of the chalk downs and set up temples at Stonehenge and Avebury on the mainland of Europe, about 1800 B.C. found that their country had become an island. The old horse pasture of North-western Europe was split into sundered provinces by the advancing sea, but the breeds, native to a lost valley are still almost identical on either shore. The Breton and British moors have {45} one type of Celtic pony whose ancestral range extended across the Straits of Dover. The clay fens of Lincolnshire and of Holland still have draught horses alike in build and in colour. The limestone districts north of the Humber have the same tall horses as the similar provinces across the water in Schleswig, Holstein and Jutland. The granitic lands of Scotland and Norway have one type of the Celtic pony. (Low's Domesticated Animals.) It is none of my business, but I cannot help feeling that the flooding at about the same period of the Lower Yukon and North River Valleys is something more than a coincidence. The Geological people are always cocksure that the sea cannot rise, that an hemisphere--the Southern, for example, cannot be flooded, and they assume quite blandly that lands have sunk, without explaining why. Their theories never seem really to fit that mighty wilderness, to which I have seen them come as visitors or strangers. Science will never understand until it learns to love. PART VIII. THE HUMAN INFLUENCE. [Sidenote: The human influence] We have now reached a stage of the argument which shows for Europe no continental type like the Bay or the Dun, but a horse stock of varied colouring, of diverse heights and {46} builds, and most curious dispersions as native to the green pastures of Cloudland. [Sidenote: Shuffling of the horse pack]