[91] H. Rosen: Die ethnographische Verhältnisse in den baltischen Provinzen und in Litauen, _Pet. Mitt._, Sept. 1915, pp. 329-333. [92] Russian census of 1897. [93] W. Z. Ripley: The Races of Europe, New York, 1899. [94] Statisko Årsbok för Finland 1914, Helsingfors, 1915, pp. 45-46. [95] Bidrag till Finlands Officiella Statistik, VI, Befolkningsstatistik, 45, Finlands Folkmängd den 31 December, 1910 (enligt Församlingarnas Kyrkoböcker), Helsingfors, 1915, p. 127. [96] Bidrag till Finlands Officiella Statistik, VI, Befolkningsstatistik, 45, Finlands Folkmängd den 31 December, 1910 (enligt Församlingarnas Krykoböcker), Helsingfors, 1915, pp. 124-125. CHAPTER VI THE AREA OF POLISH SPEECH South of the Baltic shores the unbroken expanse now peopled by Germans merges insensibly into the western part of the great Russian plain. This extensive lowland is featureless and provides no natural barriers between the two empires it connects. The area of Polish speech alone intervenes as a buffer product of the basin of the middle Vistula. The region is a silt-covered lowland, the bed of a former glacial lake. It has been peopled by Slavs for over a thousand years. Upon its open stretches there was no lack of food and no reason therefore for migration. The development of Poland rests primarily on this physical foundation. Added advantages of good land and water communication with the rest of the continent contributed powerfully to the spread of Polish power, which at one time extended from Baltic shores to the Black sea. In the ninth century the Slavic tribes of the Polish and western Russian regions differed but slightly in language and customs. Dialects spoken in the upper Vistula basin and in the upper Dnieper valley presented a degree of affinity which has disappeared from the Russian and Polish languages as spoken in our time. Differences between the two groups increased as they came respectively under eastern and western influences. Intercourse between the western group and the Slavs settled in the upper Elbe region produced a Polish contingent, while contact of the eastern body with Tatars created the main Russian group. Religious differences helped to widen the breach between these two branches of the Slavic family. The western body was naturally inclined to follow the counsels emanating from the Vatican. The eastern looked to Byzantium for spiritual guidance. These were strictly geographical relations. Eventual divergence into separate nationalities originated in the conflicts of religious views and material interests among the leading members in each group. [Illustration: FIG. 38--Sketch map of eastern Europe showing the areal classification of Russians into Little Russians (dotted area), Great Russians (diagonally ruled) and White Russians (cross-ruled area). The black dots indicate Masurian localities. The dotted circles show Hungarian cities peopled by Ruthenians.]