A second great western route must have begun very early to compete with the African. This led along the curve of the mountain ranges of Persia and Armenia, with Breasted's fertile crescent at their base, up the valley of the Euphrates and elsewhere into Asia Minor. This route continued in use as a great thoroughfare for migrating peoples and invading armies through historic times. Xenophon and his 10,000 explored it. It is surrounded on three sides by water, although mountain chains cut off the influence of the sea to some extent. It is a plateau of glade and forest, though the forests have now largely disappeared. It has the features of a semitropical climate; here the flora of northern and southern provinces meet and overlap. One great characteristic of the region is the abundance and variety of its fruit-trees. It was apparently the original home of apricot, peach, fig, and orange, as well as of other fruits introduced into Italy from this region by the Romans. The vine is luxurious. Somewhere along the line of this great thoroughfare the wild olive was domesticated, improved, and transformed. Oaks, walnuts, chestnuts, and many smaller growths furnish a variety of nuts. The open glades tempted to agriculture and furnished no small contributions of grain to Rome. Though suffering from dessication, it may yet again become the garden of the world. When once a wave of westward migration had entered Asia Minor it was walled in on the north and south by mountain and sea. There were no by-roads. Crowded and pressed from behind, it could not stop until they reached the shores of the Ægean Sea. Here there were two possible outlets. One was by sea, using as stations the islands with which the sea is dotted and leading to Crete and to Greece. Crete, according to Evans, was settled some 14,000 years ago, and is on the whole less easily reached by short voyages than Attica. A second outlet led across the Hellespont and around the Ægean Sea into Greece, or still farther northward and westward around the Adriatic and down into Italy. We might add still a third fork of this great highway running northward to the Danube. When we remember how Neolithic settlements in northern Europe clustered around the lakes and dotted the river valleys, the primitive minor routes of communication, how early islands like Crete in the south and Gothland in the Baltic were settled, we can imagine the importance of a city--or even a village--like Troy even in prehistoric times. Here a sea route running east and west crossed a great land route running north and south. Here was a point of exchange, trade, and transshipment--if we may use the word. We do not wonder that before the close of the Neolithic period, and perhaps far earlier, patterns and influences were radiating through the Balkan region, far up the Danube, and we know not how far into Russia.