Europe tribes who had already made some progress in human industry. Even in the childhood of history there existed tribes who were looked upon as aborigines, and some of their descendants—as, for instance, the Basks—have nothing in common with the invaders from the neighbouring continent. Nor is it universally admitted that the Aryans—that is, the ancestors of the Pelasgians, the Greeks, the Latins, Celts, Germans, and Slavs—are of Asiatic origin. Similarity of language may justify our belief in the common origin of the Aryans of Europe, the Persians, and the Hindoos, but it does not prove that their ancestral home should be looked for somewhere near the sources of the Oxus. Many men of learning[3] look upon the Aryans as aborigines of Europe, but certainty on this point does not exist. No doubt, in prehistoric times, intermigrations between the two continents were frequent; but we hardly know what directions they took, and can speak with certainty only of those migrations of peoples which are related by history. We thus know that Europe sent forth to other continents Galatians, Macedonians, and Greeks, and more recently innumerable emigrants of all nationalities, and received in turn Huns, Avares, Turks, Mongols, Circassians, Jews, Armenians, Moors, Berbers, and members of many other nations. [Illustration: ETHNOGRAPHICAL MAP OF EUROPE] Leaving out of consideration the smaller families of nations, as well as the members of races who have not attained a national existence, Europe may be described as consisting of three great ethnological divisions, the principal boundary between which is formed by the Alps, the Carpathians, and the Balkan. The first of these great families of European nations, the members of which speak Greco-Latin languages, occupies the southern slopes of the Balkan and of the Alps, the Iberian peninsula, France, and a portion of Belgium, as well as a few detached territories within the limits of the ancient Roman empire, altogether surrounded by alien nations. Such are the plains of the Lower Danube and a portion of Transylvania, which are inhabited by the Rumanians, and a few secluded Alpine valleys inhabited by “Romans.” On the other hand, fragments of two ancient nations have maintained their ground in the midst of Latinised populations, viz. the Celtic inhabitants of Brittany, and the Basks of the Pyrenees. Generally speaking, however, all the inhabitants of South-western Europe, whether of Celtic, Iberian, or Ligurian race, speak languages derived from the Latin, and whatever differences existed originally between these various populations, this community of language has more or less obliterated them.