Gaul was, according to the reports of the ancients, comparatively well peopled. Certain statements lead us to infer that in the Belgic districts there were some 200 persons to the square mile-- a proportion such as nearly holds at present for Wales and for Livonia--in the Helvetic canton about 245;(11) it is probable that in the districts which were more cultivated than the Belgic and less mountainous than the Helvetian, as among the Bituriges, Arverni, Haedui, the number rose still higher. Agriculture was no doubt practised in Gaul--for even the contemporaries of Caesar were surprised in the region of the Rhine by the custom of manuring with marl,(12) and the primitive Celtic custom of preparing beer (-cervesia-) from barley is likewise an evidence of the early and wide diffusion of the culture of grain--but it was not held in estimation. Even in the more civilized south it was reckoned not becoming for the free Celts to handle the plough. In far higher estimation among the Celts stood pastoral husbandry, for which the Roman landholders of this epoch very gladly availed themselves both of the Celtic breed of cattle, and of the brave Celtic slaves skilled in riding and familiar with the rearing of animals.(13) Particularly in the northern Celtic districts pastoral husbandry was thoroughly predominant. Brittany was in Caesar's time a country poor in corn. In the north-east dense forests, attaching themselves to the heart of the Ardennes, stretched almost without interruption from the German Ocean to the Rhine; and on the plains of Flanders and Lorraine, now so fertile, the Menapian and Treverian herdsman then fed his half-wild swine in the impenetrable oak-forest. Just as in the valley of the Po the Romans made the production of wool and the culture of corn supersede the Celtic feeding of pigs on acorns, so the rearing of sheep and the agriculture in the plains of the Scheldt and the Maas are traceable to their influence. In Britain even the threshing of corn was not yet usual; and in its more northern districts agriculture was not practised, and the rearing of cattle was the only known mode of turning the soil to account. The culture of the olive and vine, which yielded rich produce to the Massiliots, was not yet prosecuted beyond the Cevennes in the time of Caesar. Urban Life