The hardening of bronze was one of the most important facts affecting man's advance in the Bronze Age, and we have abundant indications (see papers in archaeological and anthropological journals by H. J. E. Peake) of man's ability to attack the forest seriously ere bronze gave place to iron. The attack on the forest was undoubtedly redoubled when man acquired iron weapons, and so the Early Iron Age witnessed extensive settlement in forest clearings in Europe north of the Alps, and with that went increase of corn-growing. South of the Alps the warming of the climate after the Ice Age had helped to reduce the forest, especially in view of the large stretches of limestone and the sharp slopes which have always hindered regrowth of forest once destroyed. The Mediterranean region, by reason of the long summer drought, has become with the establishment of its present climate less fit for pasturing of animals and more suited to the goat than {92} to cattle or sheep. As a result of this the destructive goat has reduced the forests and hindered their regrowth. The difficulty of stock-raising encouraged efforts towards cultivation, which is certainly very old in the Mediterranean region, and has passed through several phases that need elucidation. It seems probable that barley cultivation was established very early, and bee and fruit culture were gradually gathered around it, the olive proving invaluable as a substitute for animal fat. But ere the olive could be grown in quantity there had to be a good deal of organization, for it does not begin to bear till it is almost eight years old, and is in full bearing when it is nearing its thirtieth year. To wait for the olive, therefore, meant possession of some reserves and assurance of food supplies, such as imported grain, ere much land could be turned into olive groves. War and unsettlement worked against olive culture, for the risks of destruction of an olive grove were then serious, and the consequences disastrous. If, however, olive culture was, on the one hand, the result of a measure of peace and prosperity, it was also in most cases the presage of further growth of prosperity; the harvest was reasonably assured and immensely valuable, especially as it could be transported far and wide by sea. The relation of olive culture to the classical period in Greece is well known. We seem to have grounds for associating city growth in the Mediterranean with trade and the spread of large-scale olive culture as well as with the question of defence.