When the Austro-German armies reached the line of the San on May 14, 1915, the battle for mid-Galicia was over, and a fresh chapter of the campaign opened with the battle of the San, which might more fittingly be described as the battle for Przemysl. The position of Ivanoff's right has been shown; his right center lay west of the Lower San; the center east of the river covered Przemysl; his left center extended along the Upper Dniester, while his left, under Lechitsky, was keeping Von Pflanzer-Baltin employed. Von Mackensen's "phalanx" was slowly coming into action again, directing its course toward the Russian center. The "phalanx" was compelled to travel slowly, for it carried about 2,000 pieces of artillery with ample munitions, and the railroads had been wrecked by the retreating Russians. What has been described by military writers as "Von Mackensen's phalanx" was a concentration of troops along the lines on which the strongest resistance was expected or where the quickest advance was intended. No special group of forces appear to have been set apart for that purpose; there was very little shifting about or regrouping necessary during the campaign, and so well was the plan arranged that the concentrations occurred almost automatically wherever and whenever they were most needed. The infantry marched in successive lines or echelons, about forty yards apart, while in the ranks the men were allowed about four feet elbow room apiece. For frontal attacks this might be considered fairly close formation, but Von Mackensen calculated more upon the disintegrating effect of his artillery to first demoralize the enemy and wreck his position, after which the infantry came into play to complete the destruction. Without an overwhelming supply of artillery the "phalanx" plan would have been unworkable--machine guns would exact too heavy a sacrifice of life.