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smaller scale, but is most noticeable in mountainous countries, where the courses of rivers are short and steep. I refer to river terraces, those comparatively horizontal steps which are sometimes on one side and sometimes on the other, and occasionally on both, and which form a series of terraces ascending the valley; frequently varying as to difference of level, but often remarkably regular in their gradations. Many persons are under the impression that these terraces are the remains of former sea beaches; that to have formed them the sea must have covered whole continents, and reached near the tops of high mountains; that the land has either risen out of the sea, or that the sea has receded. It is difficult however to accept such explanation. For, if it were the rising of the land, it must be assumed that the land has invariably been elevated evenly, and not on an incline; which is against all modern observations. Neither can they be accounted for on the supposition of depression of the sea, for to form terraces in such marked and regular gradation, sudden depressions and stages of rest should have occurred, which would be difficult to imagine. In the Rocky Mountains these terraces are seen in the river valleys running into the mountains from the prairies at an elevation of four thousand feet above the sea-level, and thence upwards they are remarkable. Similar features occur in many parts of the world, and in Japan they exist in many localities. Now as Japan is a volcanic country and has doubtless been subject to many and frequent changes of features in what are called geological epochs, upheaval and depression by such means are unlikely to have been even, but the chances are in favour of the new form of the surface being more or less contorted or inclined. Consequently it is natural to infer that these river terraces, which we now observe with little deviation horizontal, have been formed subsequent to any great disturbances of the earth’s crust. Moreover, had the sea formed these beaches and terraces, there would have been numerous marine shells found in them. Instead of which we find them composed of stones, gravel, sand and clay, and of
