Take again for example the boundary between England and Scotland. If we follow merely the geographical conditions, we may shift the boundary line a little northward, or perhaps southward too, with better or at least equal reason. In order to account for the present boundary, we cannot but look back into the history of the district, from the age of the Picts and Britons downward. If it had been a dividing line of shorter duration dating only from the Middle Ages, it would not have been able to maintain itself so long, and the differences of not only dialects but of temperament and various mental characteristics would not have been so decisive. We have no Picts-wall, no limes in our country, but the boundary line delineated above divides Japan into two parts, the one different from the other in various ways, more remarkably than could be effected by drawing any other boundary line elsewhere. Then where lies the reason which makes the Ainu line so significant? It must be attributed to the fact that the line stood for many centuries as a frontier of the Japanese against the Ainu. In other words, the Ainu must have made the most stubborn resistance on this line against the advancing Japanese. Japan had to become organised and consolidated in a great measure, so as to be called a well-defined entity, before the Japanese could penetrate beyond the line to the east and north. The exploration of Northern Japan is the result of this penetration and of the infiltration of the civilisation which had come into being in the already compact south. Thus the difference between the two parts grew to be a clearly perceptible one. In some respects it can be well compared to the difference between Cape Colony and the two states, the Transvaal and the Orange Free State, which were formed by the emigrants from the former.