The small cemeteries may imply a rather more sedentary way of life than is demonstrable for stage III. But there is no indication of any radical change in the primary productive economy. As there, stock-breeding provided one main source of food, and again sheep bones are the commonest in the food-refuse and next bones of cattle. In addition to veal, mutton, and pork, the Shetlanders, like the systadial makers of Food Vessels, depended upon cereal foods. The richly furnished graves under huge cairns, like the dagger graves just mentioned or the largest of the Knowes of Trotty with its gold discs and amber beads belong no less certainly to chiefs. Doubtless the chiefs, interred beneath such monumental barrows, were still felt, and felt themselves, as representatives and trustees of the clans, endowed indeed with spiritual and temporal authority, but still restrained by kinship bonds.