France and England continued long after this, and their severance, he believes, was produced by the operation of existing causes. The narrow isthmus by which they were conjoined extended across the Straits of Dover, just as Africa is united to Asia by the Isthmus of Suez, or North and South America by the Isthmus of Panama. This isthmus was breached by the action of the sea on both sides, but the sea being _lower_ on the west side, the current swept with greater violence through this new channel, “toward the most huge Western Ocean, the greater divider of Europe and Africa, from the late found America.” He notices the identity of cliffs on the opposite sides of the straits, the submarine ridge which extends from Folkestone to Boulogne, the existence of marine shells all over the Netherlands and adjacent countries, and their consequent submergence before the sea was permitted to retreat through the new course produced in the isthmus, “and no way is there else to be found or imagined, whereby these seas might be drained or drawn away.” He refers to the identity also of the noxious animals in England and France, when our isle, continuing since the flood fastened by nature to the great continent, these wicked beasts did of themselves pass over; nor is the earthquake omitted by the writer, in his enumeration of causes whereby the sea, first breaking through, might afterward by little and little enlarge her passage; and the labor of man, too, had its share, when the inhabitants of the one side or the other by occasion of war did cut it, thereby to be sequestered and freed from their enemies.