When primal man, with no weapon or tool but one chipped from a stone flake, roamed over France, England and the Iberian peninsula, along with the rhinoceros, the hippopotamus and the elephant, the coast lines of Europe and North Africa were quite unlike those of to-day. England and Ireland were united to the mainland, and neither the Straits of Dover nor St. George’s Channel had been furrowed by the waves. Huge forests, such as can yet be traced near Cromer, covered the plains which are now the bottom of the German Ocean. In the broad shallow sea to the north, the mountainous regions of Scandinavia rose as islands, and between them and the Ural Mountains its waters spread uninterruptedly.
To the south, Northern Africa was united to Southern Europe by two wide land-bridges, one at the Straits of Gibraltar, one connecting Tunis with Sicily and Italy. The eastern portion of the Mediterranean was a contracted fresh-water lake, pouring its waters into a broad stream which connected the Atlantic with the Indian Oceans. This stream covered most of the present desert of the Sahara, the delta of Egypt, and a large portion of Arabia and Southern Asia. Its northern beach extended along the southern base of the Atlas Mountains from the River Dra on the Atlantic to the Gulf of Gabes in the Mediterranean; thence northward between Malta and Sicily to the Straits of Otranto; by the Ionian islands easterly till it intersected the present coast-line near the mouth of the Orontes; northeasterly to about Diarbekir, whence it trended south and east along the foot of the Zagros mountains to the Persian Gulf. From that point it followed the present coast-line to the mouth of the Indus, and thence pursued the base of the great northern mountain range to the mouth of the Ganges, covering the north of Hindustan, while the southern elevations of that spacious peninsula, as well as a large part of southern and western Arabia, rose as extensive irregular islands above the water. Toward them the mainland of equatorial Africa extended much nearer than at present. It included in its area the island of Madagascar, and reached far beyond into the Indian Ocean. Toward the north, peninsulas and chains of islands, now the summits of the plateaus and mountains of the central Sahara, reached nearly or quite to the present shore-line of the Mediterranean, about Tripolis.[40]