In the same way the digest referred to such arrears as habitual.[45] In still another letter to Trajan, Pliny observed, “Continuæ sterilitates cogunt me de remissionibus cogitare.”[46] Certainly these insolvent farmers could have held no better position when working on shares than before their disasters, for as bankrupts they were wholly in their creditors’ power, and could be hunted like slaves, and brought back in fetters if they fled. They were tied to the property by a debt which never could be paid, and they and their descendants were doomed to stay for ever as _coloni_ or serfs, chattels to be devised or sold as part of the realty. In the words of the law, “they were considered slaves of the land.”[47] The ancient martial husbandman had thus “fallen from point to point, from debt to debt, into an almost perpetual subjection.”[48] Deliverance was impossible, for payment was out of the question. He was bound to the soil for his life, and his children after him inherited his servitude with his debt. The customs, according to which the _coloni_ held, were infinitely varied; they differed not only between estates, but between the hands on the same estate. On the whole, however, the life must have been hard, for the serfs of the Empire did not multiply, and the scarcity of rural labour became a chronic disease. Yet, relatively, the position of the _colonus_ was good, for his wife and children were his own; slavery was the ulcer which ate into the flesh, and the Roman fiscal system, coupled as it was with usury, was calculated to enslave all but the oligarchy who made the laws. The taxes of the provinces were assessed by the censors and then sold for cash to the publicans, who undertook the collection. Italy was at first exempted, but after her bankruptcy she shared the common fate. Companies were formed to handle these ventures. The knights usually subscribed the capital and divided the profits, which corresponded with the severity of their administration; and, as the Roman conquests extended, these companies grew too powerful to be controlled. The only officials in a position to act were the provincial governors, who were afraid to interfere, and preferred to share in the gains of the traffic, rather than to run the risk of exciting the wrath of so dangerous an enemy.[49] According to Pliny the collection of a rent in money had become impossible in the reign of Trajan. The reason was that with a contracting currency prices of produce fell, and each year’s crop netted less than that of the year before; therefore a rent moderate in one decade was extortionate in the next. But taxes did not fall with the fall in values; on the contrary, the tendency of centralization is always toward a more costly administration. Under Augustus, one emperor with a moderate household sufficed; but in the third century Diocletian found it necessary to reorganize the government under four Cæsars, and everything became specialized in the same proportion.