Cross currents of migration can be traced in Polynesian waters, where certain islands are nodal points which have given and received of races and culture through centuries of movement.

The original white population of Uruguay differed widely from that of the other Spanish republics of South America.

Its nucleus was a large immigration of Canary Islanders.
These were descendants of Spaniards and the native Guanches of the Canaries, mingled also with Norman, Flemish and Moorish blood.[153] The Norse on their way to Iceland may have picked up a Celtic element in the islands north of Scotland; but from the Faroe group onward they found only empty Iceland and Greenland.

This was an exceptional experience.
Early navigation, owing to its limitations, purposely restricted itself to the known.

Men voyaged where men had voyaged before and were to be found.