Matters wore a different aspect, when one crossed the Roman frontier. The great Celtic nation, which in the southern districts already began to be crushed by the Italian immigration, still moved to the north of the Cevennes in its time-hallowed freedom. It is not the first time that we meet it: the Italians had already fought with the offsets and advanced posts of this vast stock on the Tiber and on the Po, in the mountains of Castile and Carinthia, and even in the heart of Asia Minor; but it was here that the main stock was first assailed at its very core by their attacks. The Celtic race had on its settlement in central Europe diffused itself chiefly over the rich river-valleys and the pleasant hill-country of the present France, including the western districts of Germany and Switzerland, and from thence had occupied at least the southern part of England, perhaps even at this time all Great Britain and Ireland;(10) it formed here more than anywhere else a broad, geographically compact, mass of peoples. In spite of the differences in language and manners which naturally were to be found within this wide territory, a close mutual intercourse, an innate sense of fellowship, seems to have knit together the tribes from the Rhone and Garonne to the Rhine and the Thames; whereas, although these doubtless were in a certain measure locally connected with the Celts in Spain and in the modern Austria, the mighty mountain barriers of the Pyrenees and the Alps on the one hand, and the encroachments of the Romans and the Germans which also operated here on the other, interrupted the intercourse and the intrinsic connection of the cognate peoples far otherwise than the narrow arm of the sea interrupted the relations of the continental and the British Celts. Unhappily we are not permitted to trace stage by stage the history of the internal development of this remarkable people in these its chief seats; we must be content with presenting at least some outline of its historical culture and political condition, as it here meets us in the time of Caesar. Population Agriculture and the Rearing of Cattle