These hunters lived on open steppes for two hundred centuries or so, ten times the length of the Christian era. They were, perhaps, overtaken by the growth of the European forests, as the climate became milder and damper. When the wild horse and the reindeer diminished in Europe, and a newer type of human culture, with a greater power over food supply, a greater tenacity of settlement, and probably a larger social organization, arose, the Reindeer Men had to learn fresh ways of living or disappear. How far they learnt and mingled their strain with the new European populations, and how far they went under we cannot yet guess. Opinions differ widely. Wright lays much stress on the “great hiatus” between the Palæolithic and Neolithic remains, while Osborn traces the likeness of the former in several living populations. In the region of the Doubs and of the Dordogne in France, many individuals are to be met with to this day with skulls of the “Cro-Magnon” type. Apparently the Grimaldi type of men has disappeared altogether from Europe. Whether the Cro-Magnon type of men mingled completely with the Neolithic peoples, or whether they remained distinct and held their own in favourable localities to the north and west, following the reindeer over Siberia and towards America, which at that time was continuous with Siberia, or whether they disappeared altogether from the world, is a matter that can be only speculated about at present. There is not enough evidence for a judgment. Possibly they mingled to a certain extent. There is little to prevent our believing that they survived without much intermixture for a long time in north Asia, that “pockets” of them remained here and there in Europe, that there is a streak of their blood in most European peoples to-day, and that there is a much stronger streak, if not a predominant strain, in the Mongolian and American races.[40] § 4