Belgium’s linguistic dualism prevailed throughout the five centuries of the Roman occupation. Intercourse at that time between the Belgae dwelling south of the Via Agrippa, and the Romans who were pushing steadily northwards was frequent and intimate. The Latin of the Roman invaders, modified by the Celtic and Germanic of native populations, gave birth eventually to the Walloon of subsequent times.[10] The Belgae of the lowlands farther north, however, successfully resisted the efforts made by the Romans to conquer them. The marshes of their nether country, and the forested area which was to be laid bare by the monks of the Middle Ages, constituted a stronghold in the shelter of which Germanic dialects took root. This forested area--the Sylva Carbonaria of the Romans--was the chief geographical feature which prevented thorough fusion of Flemings and Walloons. It was the westernmost extension of the Ardennes forests and its gloomy solitudes covered the largest part of the territory which has since become the province of Hainaut. Beyond its northern boundary lay the lands of Teutonic culture and language. To the Flemings, living north of the wooded curtain, the Gallo-Romans, who became known as Walloons, were the Walas or “foreigners” who dwelt south of the tree-studded barrier. A sharply defined line of separation intensified, in this manner, all pre-existing racial differences. At a later date, the growth of the temporal power of the Roman Church resulted in the establishment of a number of bishoprics over districts segregated irrespectively of linguistic differences. Perhaps one of the most striking features of Belgian history is found in the fact that its linguistic and political boundaries have never coincided. Every century is marked by renewal of the age-long clashes between the northern and southern races which have been thrown in contact along the western end of the line which separates the plains of northern Europe from the mountainous southland of the continent. It may be gathered from all this that the linguistic line of cleavage has undergone very little modification in the course of centuries.[11] It now divides the country into a northern section, the inhabitants of which consider Flemish as their vernacular, but who also generally understand French, and a southern section peopled by French-speaking inhabitants, who adhere to the use of Walloon dialects in the intimacy of their home life. To the east, the political frontier between Belgium and Germany does not divide the two countries linguistically. Within Prussian territory, Malmedy and a group of fifteen villages are inhabited by a French-speaking folk. As though to offset this intrusion of French speech on Prussian soil, a corresponding area of German speech is found in the Belgian province of Luxemburg around Arlon.[12] Altogether about 31,500 Belgians employ German as a vernacular. [Illustration: