Though in more modern times French has more or less triumphed in the south, two variants of the old languages persist and have acquired some literary strength; they are Provençal, in use in Provence, east of the lower Rhone, and Catalan, in use in Catalonia, and to some extent in Roussillon, modified by contact with Spanish. Needless to say the _patois_ of the peasantry of southern France retains many traces of the _langue d'oc_, and the {26} boundary between the _langue d'oc_ and _langue d'oïl_ has been traced by French scholars. A study of that boundary shows that the _langue d'oïl_ penetrated through the gate of Poitou between the Central Plateau and the barren lands of La Gatine, and established its hold in the basin of the Charente, and almost as far as the gates of Bordeaux. Farther east the lower slopes of the Central Plateau form its effective boundary; the export of men and women downhill from the plateau being apparently sufficient to restrain the general tendency to uphill spread of the language of the plain. In the Rhone valley the boundary of the _langue d'oc_ bends southwards, so that Lyons belongs to the _langue d'oïl_, and the whole Isère region is intermediate between north and south. The boundary near the Rhone is at the narrowing of the river valley near Valence. The narrow, formerly forested, section of the Rhone valley between Valence and Donzère has been a barrier in several ways; Mr. Peake has shown that it divided a Burgundian from a southern culture in the earlier phases of the Bronze Age. It was a factor in the southern boundary of the Burgundian kingdom of Theodoric's time (_c._ A.D. 520), in the boundaries of the Comté de Provence and the Comté du Valentinois, and so on. Donzère is approximately the northern limit of the olive, and the Isère basin has forests that are distinctly non-Mediterranean on its great slopes. As one journeys from the Isère region to that of Drôme and Durance one finds the aspect of the country changing from that of the forest of summer green to that of bare rock masses and a marked tendency to summer brown. [Illustration: Central France]