When each generation is decimated or destroyed in turn a race can be injured beyond recovery but it more frequently happens that the result is the annihilation of an entire class, as in the case of the German gentry in the Thirty Years’ War. Desolation of wide districts often resulted from the plagues and famines which followed the armies in old days but deaths from these causes fall most heavily on the weaker part of the population. The loss of valuable breeding stock is far more serious when wars are fought with volunteer armies of picked men than with conscript armies, because in the latter cases the loss is more evenly spread over the whole nation. Before England resorted in the present war to universal conscription the injury to her more desirable and patriotic classes was much more pronounced than in Germany where all types and ranks were called to arms. In the British Isles we find, before the appearance of the Nordic race, a Mediterranean population and no important element of Alpine blood, so that at the present day we have to deal with only two of the main races instead of all three as in France. In Britain there were, as elsewhere, representatives of earlier races but the preponderant strain of blood was Mediterranean before the first arrival of the Aryan-speaking Nordics. Ireland was connected with Britain and Britain with the continent until times very recent in a geological sense. The depression of the Channel coasts is progressing rapidly to-day and is known to have been substantial during historic times. The close parallel in blood and culture between England and the opposite coasts of France also indicates a very recent land connection, possibly in early Neolithic times. Men either walked from the continent to England and from England to Ireland, or they paddled across in primitive boats or coracles. The art of ship-building or even archaic navigation cannot go much further back than late Neolithic times. The Nordic tribes of Celtic speech came to the British Isles in two distinct waves. The earlier invasion of the Goidels, who were still in the Bronze culture, arrived in England about 800 B. C. and in Ireland two centuries later. It was part of the same movement which brought the Gauls into France. The later conquest was by the Cymric-speaking Belgæ who were equipped with iron weapons. It began in the third century B. C. and was still going on in Cæsar’s time. These Cymric Brythons found the early Goidels, with the exception of the aristocracy, much weakened by intermixture with the Mediterranean natives and would probably have destroyed all trace of Goidelic speech in Ireland and Scotland, as they actually did in England, if the Romans had not intervened. The Brythons reached Ireland in small numbers only in the second century B. C.