The Mesolithic Age in Europe is the time gap, lasting nine thousand years, between the end of the glacial period and the Neolithic. Peoples living in a Mesolithic stage of culture continued to obtain their food by hunting, fishing, and the gathering of wild vegetable products as they had in the Palaeolithic; but they now possessed one domestic animal, the dog. Technologically, the introduction of the microlithic blade, which could be used in composite tools, and the invention of the wood chopping axe, further distinguish this period.

With the retreat of the last ice cap, the fertile grasslands of the Sahara and of southwestern Asia began to dry, game became scarce, and the rain belt moved westward and northward. The microlithic technique, which had been employed during late Upper Paiaeolithic times in North Africa and the Near East, was carried across the Straits of Gibraltar and through the Caucasus and South Russia into Europe, where it spread northward and northwestward, eventually affecting the industries of the entire continent. At the same time, it was diffused into Palestine.

This cultural diffusion to the north and northwest was accompanied in the Late Mesolithic or followed in the Early Neolithic by the invasion of a people flew to Europe, a relatively small-headed, short statured, effeminate looking, Mediterranean type, of direct Galley Hill deviation, and ancestral to one branch of the modern Mediterranean race. These Mediterraneans also entered Palestine in Late Mesolithic times.

A population of Upper Palaeolithic derivation, compounded of early Aurignacian and Magdalenian elements, moved northward from Spain and the Pyrenees to western France and Germany, if not farther. In the vanguard of the northern movement was a large, broad-faced, brachycephalic type reminiscent of the brachycephalic element resident in Algeria at an earlier date. Although its geographical origin is not certain, it was definitely a member of the middle and late Aurignacian group of mixed sapiens-Neanderthaloid derivation.

En eastern Europe it is possible that the older Palaeolithic race was reinforced in early post-glacial times by an increment from the Near East, although this cannot as yet be clearly demonstrated. Invasions parallel to that which crossed Gibraltar probably entered Europe via the Caucasus, but there is at present very little evidence to support such a theory. In northwestern Europe, especially in Scandinavia and Britain, where the last glacier had its main centers and lasted the longest, Upper Palaeolithic man of the central European variety persisted through the Mesolithic, and it is to this corner of Europe that we must look for a maximum survival of glacial age European man into the present time. Similarly, the other main type which we traced during the Palaeolithic—the long-faced and long-legged ancestral Hamite of East Africa—persisted in East Africa into the Mesolithic without change.

Although most if not all of the innovations, both racial and cultural, which reached Europe during the Mesolithic Age, came from North Africa and also perhaps from points farther east, we may suppose that events of far greater importance to human history were going On at this time on the continent of Asia, There the peoples of the western plateaux must have already begun the mastery of the animal and vegetable worlds which was to permit them to increase in numbers, and to overflow into Europe, thus marking the beginning of the Neolithic period in the latter continent. If we are to understand the racial changes which affected the population of Europe at the end of the Mesolithic, we must next devote our attention to these imminent invaders.