Secondly, at the close of the palanthropic age we find a great change in land animals--a number of important species hunted by early man having disappeared, and the more meagre modern fauna having come in at once. Thus it may be affirmed that the land fauna of this primitive time was distinct from that now living. This implies either long time or a great physical break. Thirdly, this change of fauna consists not so much in the introduction of new species as in the extinction of old forms, either absolutely or locally; and this agrees with the fact of diminution of land area, since it seems to be a law of the geological succession that increasing land brings in new land animals; diminishing land area leads to extinction, and not to introduction. Fourthly, in accordance with this we find that, at the close of the palanthropic age, the continents of the northern hemisphere experienced a subsidence from which they have only partially recovered up to the present time, and which introduced the modern geographical and climatal features. This appears from raised beaches and beds of rubble, loam and loess of modern date overlying the _débris_ of the glacial period and holding the remains of post-glacial animals. These are widely spread over the whole northern hemisphere, and ascend in some districts to high levels. An interesting illustration has recently been given by Dr. Nuesch and M. Boule, in the deposits under a rock-shelter at Schweizersbild, near Schaffhausen.[25] These show an overlying deposit with 'neolithic' implements and bones of recent animals, a bed of rubble and loam destitute of human remains, and below this a bed containing bone implements, worked flints, and traces of cookery of the palanthropic period. The whole rests on a bed of rolled pebbles, supposed to be the upper part of the glacial deposits. This shows the interval between the palanthropic and neanthropic periods, and also the post-glacial date of man in Switzerland, and it accords with a great many other instances. [25] _Nouvelles archives des Missions_, &c. vol. iii. Noticed in _Natural Science_, 1893.