black lava and red loam, rich in plant food and retentive of moisture, overlying the limestone which elsewhere forms the surface rock. The archaeological remains range from great stones erected by primitive men to ruins of Roman and Byzantine roads, aqueducts, reservoirs, buildings and fortifications which testify to its once-thriving condition as a granary of the empire. Today it still provides Palestine and Lebanon with wheat as it did in the days of the Hebrews and the Phoenicians.
South of Hawran, in Transjordan proper, the eastern highlands continue through the hills of Gilead to the high tableland of Moab. East of Petra the sandstone strata attain a height of 4430 feet before merging with the stony desert of Arabia.
The great wasteland called the Syrian Desert is the fifth and last distinct zone in Syrian structure. The desert proper, which is separated from the highlands by a transition zone of steppes, volcanic tracts and sands, is a continuation of the great Arabian Desert, forming a huge triangular bay which separates settled Syria from the river valleys of Iraq. Its maximum width approximates 800 miles. Its nomadic denizens trade with the settled population on both sides, act as middlemen, guides and caravaneers, and in remote times built such cities as Palmyra, which lay on the trans-desert route between Syria and Mesopotamia. Their blood has always been a perennial reservoir of biological vitality to the urban population, supplying it with fresh infusion either through conquest or by peaceful penetration. But normally bedouins resist the temptation to settle down and, in quest of pasture for their flocks, they roam the desert plains, living off the grass which blankets it after every shower of rain. Bedouin hospitality to guests does not imply any corresponding hospitality to innovations. If the mainspring of progress in a settled community lies in the attempt to change and adapt the conditions of life and environment, the secret of survival in a nomadic community consists in
