The enclosed or marginal sea seems a necessary condition for the advance beyond coastwise navigation and the much later step to the open ocean.  Continents without them, like Africa, except for its frontage upon the Mediterranean and the Red Sea, have shown no native initiative in maritime enterprise.  Africa was further cursed by the mockery of desert coasts along most of her scant thalassic shores.  In the Americas, we find the native races compassing a wide maritime field only in the Arctic, where the fragmentary character of the continent breaks up the ocean into Hudson’s Bay, Davis Strait, Baffin Bay, Gulf of Boothia, Melville Sound and Bering Sea; and in the American Mediterranean of the Caribbean Sea and Gulf of Mexico.  The excellent seamanship developed in the archipelagoes of southern Alaska and Chile remained abortive for maritime expansion, despite a paucity of local resources and the spur of hunger, owing to the lack of a marginal sea; but in the Caribbean basin, the Arawaks and later the Caribs spread from the southern mainland as far as Cuba.[555] [See map page 101.]

[Sidenote:  Enclosed seas as areas of ethnic and cultural assimilation.]

Enclosed or marginal seas were historically the most important sections of the ocean prior to 1492.  Apart from the widening of the maritime horizon which they give to their bordering people, each has the further advantage of constituting an area of close vicinal grouping and constant interchange of cultural achievements, by which the civilization of the whole basin tends to become elevated and unified.  This unification frequently extends to race also, owing to the rapidity of maritime expansion and the tendency to ethnic amalgamation characteristic of all coast regions.  We recognize an area of Mediterranean civilization from the Isthmus of Suez to the Sacred Promontory of Portugal, and in this area a long-headed, brunette Mediterranean race, clearly unified as to stock, despite local differentiations of culture, languages and nations in the various islands, peninsulas and other segregated coastal regions of this sea.[556] The basin appears therefore as an historical whole; for in it a certain group of peoples concentrated their common efforts, which crossed and criss-crossed from shore to shore.  Phoenicia’s trade ranged westward to the outer coasts of Spain, and later Barcelona’s maritime enterprises reached east to the Levant.  Greece’s commercial and colonial relations embraced the Crimea and the mouth of the Rhone, and Genoa’s extended east to the Crimea again.  The Saracens, on reaching the Mediterranean edge of the Arabian peninsula, swept the southern coasts and islands, swung up the western rim of the basin to the foot of the Pyrenees, and taught the sluggish Spaniards the art of irrigation practiced on the garden slopes of Yemen.  The ships of the Crusaders from Venice, Genoa and Marseilles anchored in the ports of Mohammedanized Syria, brought the symbol of the cross back to its birthplace In Jerusalem, but carried away with them countless suggestions from the finished industries of the East.  Here was give and take, expansion and counter-expansion, conquest and expulsion, all together making up a great sum of reciprocal relations embracing the whole basin, the outcome of that close geographical connection which every sharply defined sea establishes between the coasts which it washes.