Hitherto men in Europe had never gone farther north than the Baltic Sea or the English midlands, but now Ireland, the Scandinavian peninsula, and perhaps Great Russia were becoming possible regions for human occupation. There are no Palæolithic remains in Sweden or Norway, nor in Ireland or Scotland. Man, when he entered these countries, was apparently already at the Neolithic stage of social development. § 5 Nor is there any convincing evidence of man in America before the end of the Pleistocene.[43] The same relaxation of the climate that permitted the retreat of the reindeer hunters into Russia and Siberia, as the Neolithic tribes advanced, may have allowed them to wander across the land that is now cut by Bering Strait, and so reach the American continent. They spread thence southward, age by age. When they reached South America, they found the giant sloth (the _Megatherium_), the glyptodon, and many other extinct creatures, still flourishing. The glyptodon was a monstrous South American armadillo, and a human skeleton has been found by Roth buried beneath its huge tortoise-like shell.[44] All the human remains in America, even the earliest, it is to be noted, are of an Amer-Indian character. In America there does not seem to have been any preceding races of sub-men. Man was fully man when he entered America. The old world was the nursery of the sub-races of mankind. XI NEOLITHIC MAN IN EUROPE[45] § 1. _The Age of Cultivation Begins._ § 2. _Where Did the Neolithic Culture Arise?_ § 3. _Everyday Neolithic Life._ § 4. _How Did Sowing Begin?_ § 5. _Primitive Trade._ § 6. _The Flooding of the Mediterranean Valley._ § 1 THE Neolithic phase of human affairs began in Europe about 10,000 or 12,000 years ago. But probably men had reached the Neolithic stage elsewhere some thousands of years earlier.[46] Neolithic men came slowly into Europe from the south or south-east as the reindeer and the open steppes gave way to forest and modern European conditions.