Between Europe and Asia the great movements of peoples have followed two parallel directions north or south of the central belt of high Eurasian mountains extending from east to west. Men have traveled back and forth in these two lines from the earliest known period. But exchange of ideas has been practically confined to the southern avenue. In the cold of the Siberian or northern European lowlands men had little opportunity to acquire refinement. They were active and energetic, while the followers of the southern pathways were thinkers. From the dawn of history to our day only two departures of importance have taken place from this east-west traffic. Both were modern events. One occurred in the middle of the fifteenth century as soon as the Turks acquired mastery of western Asia and the Balkan peninsula. The Christian sailor-trader of that time was then obliged to circumnavigate Africa in order to reach eastern seaports. The other change took place when the Suez Canal was completed. This waterway diverted to its channel much of the overland Asiatic traffic routed between the Black Sea and the Persian Gulf or the Indian Ocean. But even these two diversions failed to eliminate entirely the picturesque caravans which plied over Turkish roads. Thus it may be assumed that these routes have been used uninterruptedly for about 10,000 years at least, that is to say, before the time in which their known history begins. The southeastern portal of these celebrated highways is situated at the head of the Persian Gulf. The broad Tigris and Euphrates thence mark the northerly extension of the routes. On the western river, the natural road leaves the valley above Mosul and penetrates into the Armenian highland through the gorges in the neighborhood of Diarbekir. The very name Mosul, a contraction of the Greek “Mesopylae” or Central Gates, suggests its origin. The city grew at the meeting point of routes from the Caspian, Black and Mediterranean seas and from the Persian Gulf. The through highway links once more with the Euphrates in its upper reaches around Keban Maden in order to reach the Anatolian plateau. The passes are precipitous and the waters flow southward closely hemmed in by steep and rocky barriers. Access to the billowy surface of Armenian mountain lands is obtained by means of either the Murad Su or the Kara Su. The union of these two rivers into the single watercourse known as the Euphrates at a short distance above Keban Maden has at all times attracted much of the traffic and travel between Armenia and Mesopotamia. The eastern affluents of the Tigris south of Lake Van, on the other hand, reach the uplifted core of Armenia where they are lost in the tangle of steep valleys and deeply broken surfaces.