The Arab folk, sparsely distributed over the Syrian desert and forming the majority of the inhabitants of the featureless downs of Mesopotamia, represent the ebbing of the last tide of Semitic invasion. In the sandy waste of their western extension, their tribes, shifting perpetually from seat to seat, like the dunes around which they roam, consist of Bedouin or “tent men.” The contribution of these nomads to society is as insignificant as the yield of the unproductive lands of their wandering. Towards the east, however, where two mighty rivers bring fertility and life to the soil, the genius of the race blossomed untrammeled and gave Mohammedan civilization to the world. The purest living representatives of the Semitic race are found among these Bedouins. Civilization pursued its steady growth around their tent homes without affecting their lives. Better favored belts encircling the Syrian desert attracted the human migrations which took place in western Asia. From the last outliers of the hill system fringing the southern Taurus to the northern confines of the Arabian peninsula, the patriarchal state of society prevailing today differs little from the condition in which a dreamer well past middle age found it fourteen centuries ago and brought it within the pale of modern thought by inspiring it with the enthusiasm of his own belief in a single God. Stripped of his religion and of his rifle, the Bedouin stands today before the historian as the living image of long remote ancestors whose invasions caused profound upheavals in the societies established east and west of his present tramping ground. But the Arab settled in the long elongated plain watered by the Tigris and Euphrates can never lay claim to equal purity of stock. He lives in a land which by virtue of a great twin river system gave rise to the oldest civilization of the world. Its inhabitants, whether aboriginal or invaders from the table-land on the east, derived more than mere sustenance from proximity to these mothering watercourses. Surrounded by desert and mountain, this region naturally became a seat of population. Its native element, already much mixed, was assimilated to a large extent by the Arabs since the period of their appearance in Mesopotamia. The floating masses of Bedouins have successfully resisted Turkish effort to induce them to abandon nomadism. Occasionally, as in the belt of Tauric precipitation or along the borders of the zone of Mediterranean rains no less than under the benign influence of Mesopotamian rivers, they become sedentary. They are then known as _fellaheen_. But the change is incompatible with their immemorial restlessness and implies loss of caste in their own eyes. TABLE I NAMES AND PEOPLES OF SOME NON-TURKISH VILLAGES IN ASIA MINOR