It is to be noted especially, that although in a few cases a difference is made between the division for royal assessment and for the manorial impositions, in the great majority of cases no such difference exists, and the duties in regard to the king and to the lord are reckoned according to the same system of holdings. On the manors of Ely, for instance, the 12 _acreware_[496] form the basis of all the reckoning of rents and work. And so if the royal assessment appear with the features of an artificial fiscal arrangement, the same observation has to be extended to the manorial assessment; and thus we reach by another way the same conclusion which we drew from an analysis of the single holding and of its component parts. No doubt the whole stands in close relation to the reality of cultivation and land-holding, but the rigidity, regularity, and correctness of the system present a necessary contrast to the facts of actual life. As the soil could not be made to fit into geometrical squares, even so the population could not remain without change from one age to the other within the same boundaries. Thus in course of time the plough-land of 160 and 180 acres, which is the plough-land of practical farming, appears by the side of the statutory hide of 120 acres; and so again inside every single holding there comes up the contrast between its real conformation and distribution, and the outward form it assumed in regard to the king, the lord, and the steward. [Rules of inheritance.]