It seemed as if the Franks, in their irresistible advance, were going to wipe out from Belgium and Gaul all trace of Roman civilization, and such a catastrophe would no doubt have occurred, if a natural obstacle had not broken their impetus. We mentioned above that, south of a line running from Dunkirk to Maestricht, the country was covered with a thick forest, the "Silva Carbonaria." This wall of wood did more to stop the invaders than the heroic efforts of AEtius. It sheltered the Celts from the Franks in Belgium as the mountains of Wales and the hills of Cornwall sheltered them from the Saxons in Great Britain. Conquests were pursued by the Frankish kings and their nobles, but the invasion stopped. The movement ceased to be ethnical and became political. The Franks reached the clearings of the forest and nominally subjected Gaul to their power, but they were now in a minority, and the conquered soon succeeded in absorbing the conquerors. It is significant that the "Lex Salica," the oldest document in which the name of the Coal Wood is mentioned, describes it as "the boundary of the territories occupied by the Frankish people." To the north of this boundary the country was entirely in the hands of the invaders; to the south, the "Wala," as the Franks called the Belgo-Romans, succeeded in maintaining themselves and in preserving to a certain extent the Roman language and civilization. The old limit, running in a northerly direction and dividing in the past "Germania Inferior" from "Belgica Secunda," had been bent under the pressure of the Frankish invasions, and ran now from east to west, but the dualism which we noted above had not disappeared. The Franks settled in the north, the romanized Celts or "Walas" occupied the south. The first are the ancestors of the Flemings of to-day, the second of the Walloons, and the limit of languages between the two sections of the population has remained the same. It runs to-day where it ran fourteen centuries ago, from the south of Ypres to Brussels and Maestricht, dividing Belgium almost evenly into two populations belonging to two separate races and speaking two different languages. The ancient forest has disappeared, but its edge is still marked on the map. We cross it to-day without noticing any alteration in the landscape, but the distant voices of the peasants working in the fields remind us of its ancient shadow and impassable undergrowth. The traveller wonders, one moment, at the change, then takes up the road again, adding one further unanswered question to his load of unsolved problems. The historian evokes the terrible years of the fifth century, when the fate of Europe hung in the balance and when the surging waves of Pagan Germanism spent their last energy along that leafy barrier which saved Christianity and Roman civilization, and incidentally gave the Belgian nation its most prominent and interesting character. The singsong of a Walloon sentence