been much freer from ethnic interference, especially in the early days when navigation across seas was a hazardous proceeding. Only in the extreme south do we have occasion to note racial
invasions along the coast. The absence of protected waters and especially of good harbors, all along the middle portion of the peninsula has not invited a landing from foreigners. Open water ways have not enabled them to press far inland, even if they disembarked. These simple geographical facts explain much in the anthropological sense. They meant little after the full development of water transportation, because thereafter travel by sea was far simpler than by land. Our vision must, however, pierce the obscurity of early times before the great human invention of navigation had been perfected.