=The Philistine Plain.= The only natural barrier that separates the plains of Sharon and Philistia is the river which comes down in two branches from the eastern hills, one branch leading westward past the Beth-horons and the other through the Valley of Ajalon. After much twisting and turning, and under many local names, this, the largest river south of Carmel, finds the sea a little north of Joppa. Southward the Plain of Philistia, about forty miles in length, broadens until it is twenty miles wide. The low hills of the Plain of Sharon change first into long, rolling swells and then throughout much of the distance settle into an almost absolutely level plain. In the southwest the sands of the sea have come in many miles. Ashkelon now lies between a sea of water and a sea of sand. At many other points the yellow waves are steadily engulfing the cultivated fields. Three perennial streams, with sprawling confluents, cut their muddy course across this rich alluvial plain. It is one of the important grain fields of Palestine, for the subsoil is constantly saturated with the moisture which falls in abundance in the winter and spring. No barns are necessary, for the grain is thrashed and stored out under the rainless summer skies. It is a land well fitted to support a rich and powerful agricultural civilization. Like all the coast plains, it is wide open to the trader and to the invader. Its possessors were obliged to be ever ready and able to defend their homes from all foes. Its inhabitants necessarily dwelt in a few strongly guarded cities. Here in ancient times, especially on the eastern side, were found the city-dwelling Canaanites. Later the valiant, energetic Philistines established their title to these fruitful plains and maintained it for centuries by sheer enterprise and force of arms. The chief Philistine cities were Ekron and Ashdod in the north, Askelon by the shore, quite close to the Judean foot-hills and Gaza^{(5)} in the southwest. Except during the heroic Maccabean age, the Israelites never succeeded and apparently never seriously attempted to dispute this title. Lying on the highway that ran straight on along the coast to Egypt, this part of Palestine was most exposed to the powerful influences that came from the land of the Nile. The oldest Egyptian inscriptions, as well as the results of recent excavations, all reveal the wide extent of this influence.