Gaul presented the same contrast of climates which we observe between the north and south of France. While the Roman province enjoyed a mild temperature and an extreme fertility,[43] the central and northern part was covered with vast forests, which rendered the climate colder than it is at present;[44] yet the centre produced in abundance wheat, rye, millet, and barley.[45] The greatest of all these forests was that of the Ardennes. It extended, beginning from the Rhine, over a space of two hundred miles, on one side to the frontier of the Remi, crossing the country of the Treviri; and, on another side, to the Scheldt, across the country of the Nervii.[46] The “Commentaries” speak also of forests existing among the Carnutes,[47] in the neighbourhood of the Saône,[48] among the Menapii[49] and the Morini,[50] and among the Eburones.[51] In the north the breeding of cattle was the principal occupation,[52] and the pastures of Belgic Gaul produced a race of excellent horses.[53] In the centre and in the south the richness of the soil was augmented by productive mines of gold, silver, copper, iron, and lead.[54] The country was, without any doubt, intersected by carriage roads, since the Gauls possessed a great number of all sorts of wagons,[55] since there still remain traces of Celtic roads, and since Cæsar makes known the existence of bridges on the Aisne,[56] the Rhone,[57] the Loire,[58] the Allier,[59] and the Seine.[60] It is difficult to ascertain exactly the number of the population; yet we may presume, from the contingents furnished by the different states, that it amounted to more than seven millions of souls.[61] [Sidenote: Political Divisions.] II. Gaul, according to Cæsar, was divided into three great regions, distinct by language, manners, and laws: to the north, Belgic Gaul, between the Seine, the Marne, and the Rhine; in the centre, Celtic Gaul, between the Garonne and the Seine, extending from the ocean to the Alps, and comprising Helvetia; to the south, Aquitaine, between the Garonne and the Pyrenees.[62] (_See Plate 2._) We must, nevertheless, comprise in Gaul the Roman province, or the Narbonnese, which began at Geneva, on the left bank of the Rhone, and extended in the south as far as Toulouse. It answered, as nearly as possible, to the limits of the countries known in modern times as Savoy, Dauphiné, Provence, Lower Languedoc, and Roussillon. The populations who inhabited it were of different origins: there were found there Aquitanians, Belgæ, Ligures, Celts, who had all long undergone the influence of Greek civilisation, and especially establishments founded by the Phocæans on the coasts of the Mediterranean.[63]