It would appear that the remnants of the Neanderthals in the late Mousterian stage of culture were stimulated by the arrival of the Crô-Magnons to imitate new flint forms and adopt the new methods of workmanship. There is no other evidence to indicate that the Crô-Magnons came into contact with communities of the Neanderthals. In these far-off days Europe was thinly peopled by hunters who dwelt in caves. The climate was cold, and the hairy mammoth and the reindeer browsed in the lowlands of France and Germany. Italy was linked with Africa; the grass-lands of North Africa stretched southward across the area now known as the Sahara desert, and dense forests fringed the banks of the River Nile and extended eastward to the Red Sea.
Neanderthal man had originally entered Europe when the climate was much milder than it is in our own time. He crossed over from Africa by the Italian land-bridge, and he found African fauna, including species of the elephant, rhinoceros, hippopotamus, lion, and the hyæna, jackal, and sabre-tooth tiger in Spain, France, Germany. Thousands of years elapsed and the summers became shorter, and the winters longer and more severe, until the northern fauna began to migrate southward, and the African fauna deserted the plains and decaying forests of Europe. Then followed the Fourth Glacial phase, and when it was passing away the Neanderthals, who had long been in the Mousterian phase of culture, saw bands of Crô-Magnons prospecting and hunting in southern Europe. The new-comers had migrated from some centre of culture in North Africa, and appear to have crossed over the Italian land-bridge. It is unlikely that many, if any, entered Europe from the east. At the time the Black Sea was more than twice its present size, and glaciers still blocked the passes of Asia Minor.
A great contrast was presented by the two types of mankind. The short, powerfully built, but slouching and slow-footed Neanderthals were, in a conflict, no match for the tall, active, and swift-footed Crô-Magnons, before whom they retreated, yielding up their flint-working stations, and their caves and grottoes. It may be, as some suggest, that fierce battles were fought, but there is no evidence of warfare; it may be that the Neanderthals succumbed to imported diseases, as did so many thousands of the inhabitants of the Amazon Valley, when measles and other diseases were introduced by the Spaniards. The fact remains that the Neanderthals died out as completely as did the Tasmanians before the advance of British settlers. We do not know whether or not they resisted, for a time, the intrusion of strangers on their hunting-grounds. It may be that the ravages of disease completed the tragic history of such relations as they may have had with the ancestors of Modern Man.