(4) All this, however, is only partially relevant to the question of the supplies of Rome from Sicily, Sardinia, Africa, and Spain in the second century B.C. Did such supplies come, or did they not? As the Professor admits, they were "vital" to the Roman military policy; and "she had immense granaries at her disposal whenever she required them." But such sources of supply meant a certain large normal production; and this would enter Italy in time of peace. If it was purposely maintained in view of the needs of war-time, so much the more surely would it undersell Italian wheat, raised on a less fruitful soil. In no other way could Sicily and Africa yield either annual tribute to Rome or rents to Roman owners of land in those countries. The first effect of the importation would be to add the pressure of lowered prices to the discouragement already offered to private cultivators by the inducements of loot in war, fleecings in administration of newly conquered countries, commerce, and usury. Of this discouragement the sequel would be the attempt to run by slave labour the large estates in which the old farms were merged. But slave labour is apt to be bad labour, and agriculture could not thereby be restored. (5) The thesis that agriculture was _depressed_ by high cost of living (= high prices for agricultural products) it is not easy to treat with seriousness. The simple fact is that sea-carriage to Rome from Sicily, Spain, and Africa must have been cheaper than land carriage from most parts of Italy to the capital. As Prof. Ferrero notes, food prices in the valley of the Po were very low--obviously because cost of carriage either to Rome or to the southern seaports deterred export.