Upper Paleolithic time, beginning with the arrival of the Cro-Magnons, about 25,000 years ago, is divided into four epochs, or, better, four culture-stages: Aurignacian, Solutrean, Magdalenian, and Azilian-Tardenoisian. Even in late Magdalenian days, after a cold and dry interval accompanied by steppe conditions and a new formation of loess, the air became moister and the temperature gradually moderated until it became much like that of to-day. Tundra and steppe animals became more rare; a forest and meadow fauna took possession of Europe. Instead of the reindeer we find stag and roe-deer, cattle, wild boar, bears and wolves, beaver and otter. These were less easily hunted and probably less abundant than the reindeer and horse had been. As hunting became less profitable, fishing grew more attractive. The streams probably swarmed with fish, and the salmon was probably as abundant throughout northern Europe as in Scandinavia to-day. A change of life is suggested by the implements. The harpoons became ruder. The beautifully flaked lance-heads and the smoothed bone daggers give place to small flints, "microliths," less fitted for attacking large and dangerous animals. The country seems to have supported a smaller and decreasing population. Cro-Magnon man had always been a reindeer hunter, accustomed and well adapted to the life and conditions of tundra or steppe. The changes were not in his favor or to his liking. Many probably left France and Germany. Those who remained deserted the rock-shelters and cave-mouths, where every spring the water seeping down and dripping through the roof dislodged masses of stone.[25] The shelter was less needed. Men dwelt more in the open, and fewer records of their presence were preserved. But Europe was not deserted. There was no "hiatus." Other peoples were coming in, perhaps better suited to the new conditions, probably mostly of Asiatic origin. Broad-heads, as well as new long-heads, appear, less attractive physically and mentally, but apparently of tougher fibre and greater staying power than our more striking and charming Cro-Magnons.[26] A new grand mingling of peoples had already begun or was in its last stages of preparation already advancing from afar in successive waves. In Italy genuine Neolithic culture may already have been introduced. It steals very slowly into northern Europe and overspreads it. The Cro-Magnon race generally migrated or died out, but left its traces in the physical characters of the people of Dordogne and elsewhere. The Azilian-Tardenoisian epoch leads over to the Neolithic, our chief object of study. Its relative position in prehistoric time is shown in the following scheme: _A._ _Eolithic Period._ Stone implements exceedingly rude, hardly recognizable as artificially chipped; otherwise like _B_. _B._ _Paleolithic Period._ Stone implements chipped or flaked, never polished. No domesticated plants or animals. No pottery. Man a collector or hunter, more rarely a fisherman.