In thus spreading out, the Alps lose their character and aspect. We no longer meet with grand mountain masses, glaciers, and snow-fields. Towards the north they gradually sink down into the valley of the Danube; towards the south they branch out into secondary chains, resting upon the arched plateau of Turkey. But, in spite of the vast contrasts offered by the true Alps and the mountains of Montenegro, the Hæmus, the Rhodope, and the Pindus, all these mountain chains nevertheless belong to the same orographical system. The whole of the Balkan peninsula must be looked upon as a natural dependency of the Alps; and the same applies to Italy, for the chain of the Apennines is nothing but a continuation of the Maritime Alps, and we hardly know where to draw the line of separation between them. The Carpathians, too, must be included among the {11} mountain chains forming part of the system of the Alps. They have been gradually separated from them through the continuous action of water, but there can be no doubt that, in former times, the semicircle of mountains known as the Little Carpathians, the Beskids, the Tatra, the Great Carpathians, and the Transylvanian Alps was joined, on the one hand, to the Austrian Alps, and on the other to spurs descending from the Balkan. The Danube has forced its way through these mountain ramparts, but the passages, or “gates,” are narrow; they are strewn with rocks, and commanded by what remains of the ancient partition ranges. The configuration of the Alps, and of the labyrinthine mountain ranges branching off from them towards the east, could not fail to exercise a most powerful influence upon the history of Europe and of the entire world. The only high-roads known to barbarians are those traced out by nature herself, and they were consequently able to penetrate into Europe only by sea, or through the vast plains of the north. Having penetrated to the westward of the Black Sea, their progress was first stopped by the lakes and difficult swamps of the Danubian valley; and, when they had surmounted these obstacles, they found themselves face to face with a barrier of high mountains, whose intricate wooded valleys and declivities led up to the inaccessible regions of eternal snow. The Alps, the Balkan, and all the other advanced chains of the Alpine system constituted an advanced defensive barrier for Western Europe, and the conquering nomad tribes who threw themselves against it did so at the risk of destruction. Accustomed to the boundless horizon of the steppes, they did not venture to climb these steep hills—they turned to the northward, where the vast plains of Germania enabled successive swarms of immigrants to spread over the country with greater ease. And as to the invaders, whom blind rage of conquest impelled to engage in the defiles of these mountains, they found themselves caught as in a trap; and this accounts for the variety of nations, and of fragments of