_The Distribution of Land and Water._—The Iroquois Indians call the peace-belt of wampum which is exchanged between friendly tribes a “river,” because it unites, as does some smooth watercourse, those living apart. This is a sweet native tribute to the influence of navigable streams in bringing man into relation to man. Bays, fiords, and harbours permitted man with frail early craft to keep along the seashore for thousands of miles. Thus the Tupis migrated from the river La Plata to beyond the mouth of the Amazon and far up that stream; while, antedating history, the Mediterranean peoples dared the stormy Iberian coast to visit the remote Cassiterides and the boreal isles of Thule. The Delaware Indians expressed their relationship among themselves by saying, “We drink the same water,” meaning that they all dwelt on the Delaware River and its tributaries. Thus watersheds, through the facility of intercourse they offered, became natural national areas, and developed unity of thought and feeling. Lake-districts exerted a like influence and became not only strongholds by their pile dwellings, but centres of tribal unity. When Cortes reached the valley of Mexico he found the shores of the lake occupied by three nations, independent but closely federated for offence and defence. These are examples of the unifying powers of the watery elements; but in its might as a torrential stream or as “the unplumbed, salt, estranging sea,” it severs the families of men with a no less stringent potency. No more striking example can be offered than that of the American race, the so-called “Indians” of our continent. They extended over the whole area from the austral to the boreal oceans, a race-unit, identical in anatomical traits, but absolutely isolated from the rest of mankind, not a trace of European, Asiatic, or Polynesian influence in their languages or cultures. The land areas offer obstacles more frequently than facilities to tribal intercommunication. Mountain chains, deserts, steppes, vast swamps, dense forests, and tangled jungles isolated by formidable barriers the early hordes, leaving them to battle singly with the difficulties of existence. The Roman writers say that interpreters for seventy different languages were needed in the Caucasus, and de Leon pretends that in the mountains of Ecuador there were as many tongues as there were villages. That Egyptian and Babylonian civilisation flourished contemporaneously for five thousand years without either colouring the other is explained by the trackless and arid desert which lay between them.