and the Baltic were united by that “ocean-river” of which Homer, Hesiod, and all the old bards sing, and by sailing along which, both the Argonauts and Ulysses are reported to have passed northwards into the western ocean. The existence of this vast belt of water, stretching from the southmost point of the Baltic to the Caucasus, is probably one reason why the Slavonians were late of appearing in southern Europe, and why no sprinkling of them or of the Mongols is to be found among the early settlers of South-western Europe. All the early migrations into Europe proceeded from Caucasian or sub-Caucasian regions—a circumstance which, considering the known simultaneous existence of roving hordes and a great population on the Mongolian plains, can hardly be accounted for on the supposition that the face of Eastern Europe has since then undergone no change. But on the supposition we make, the chain of the Ural Mountains and this large Mediterranean basin would for long act as restraints upon any tendency of the Mongolian population to move westward, or of the Slavonians to move southwards.[31] The next wave of population which flowed westwards was the Cimbri or Cimmerians,—a people cognate to the Celts or Gaels, yet by no means closely related. About the seventh century B.C., as may be inferred from Herodotus, a clan of this race abandoned the Tauric Chersonese, and marched westwards,—this Cimbrian migration, however, like most others, not being conducted in one mass, but by successive and sometimes widely-severed movements. Three centuries afterwards we find the Cimbri on the shores of the Northern Ocean in Jutland; and between the years 113 and 101 B.C., we find the race all on the move, and setting out on that southward career of devastation which eventually brought them into Gaul, Spain, and Italy. The Belgians seem to have been a Cimbrian tribe which had preceded the main body; for when, in this invasion, the Cimbri reached Northern Gaul, the Belgæ immediately joined them as allies against the Celts,—and it seems also proven that the Cimbri and Belgæ spoke dialects of the same language. The Celts, routed by the invaders, were impelled to the south and east, doubtless trespassing in turn upon the dark-skinned Iberians. It was immediately after this inroad that Cæsar and his Romans entered Gaul, and commenced his Commentaries with the well-known statement:—“All Gaul is divided into three parts, of which one is inhabited by the Belgians, [or Cimbri, in the north]—another by the Aquitanians [or Iberians, in the south-west],—and the third [or eastern], by those who in their own language, call themselves Celts, and who in our tongue are called Gael (_Galli_). These races differ among themselves by their language, their manners, and their laws.” Previous to this time the Teutons had settled in central Europe, and in alliance with Celtic tribes made incursions into Italy.