A mere glance is sufficient to show that the limits of costumes have been most changed; but, on the contrary, there is a striking resemblance from the point of view of the distribution of languages and, especially, from that of the kind of dwellings. The Frisian and Saxon influences agree on the different charts, while the types of the Upper Meuse are found everywhere that the architecture of the Roman villas has been preserved. Hence it is not astonishing that these types of the Meuse resemble those found in the valley of the Po and on the Adriatic Sea. These observations agree with the historical researches which, have established the fact that the countries bordering on the North Sea were inhabited by the Celts who came from the East to Central and Western Europe several centuries before our era. The Celts drove out the Mongols, who were already settled there; but they, in their turn, were driven from the West by the Germans. This is what caused the Romans to say that, north of the Rhine, the Celts had already been driven out everywhere by the Germans. The Rhine was at that time the general boundary line between the two peoples. South of this river there only a few German out-lying positions, like those of the Eburones at Maestricht and Roermond, and of the Condrosii near Liége. The Germans and Celts are confounded along the Meuse. The Celts in North Brabant had already become very much germanized, while the Menapii, the Morini and the Nervii of Flanders and Zeeland also felt this influence. All these germanized Celts were called Gauls by the Romans. The Germans penetrated several times into Gaul, they even came as far as the Menapian country in the valley of the Scheldt; but Cæsar succeeded in driving them back, in the year 55 B. C. After the latter’s conquests, the Rhine became the frontier of Roman domination and so remained until about the IXth century. The Gauls quickly became latinized. North of the Rhine, the Roman influence made itself felt on the Batavi, the Chamavi and the Frisians. Still, this influence was not very strong, especially on the last-named tribe. From the moment that the Roman power began to weaken, the Germans reappeared, and it was especially the Franks who proved to be the stronger. These latter, who inhabited the region of the Lippe, the Ruhr and the Upper Ems, were probably being pushed out already at this time by the Saxons. The Franks were again driven beyond the Rhine by the Emperor Probus, in 280, but they advanced again toward the South after the death of Constantine the Great (337). Cologne fell into their hands and they appeared in front of Treves. Julian prevented, however, their entering Taxandria, the present North Brabant.