The Plebeians were being recognised for the first time as, in a sense, members of the state. The first problem was the choice of a medium through which they should be incorporated in it; for simple membership of a state which was not based on membership of some lower unit was inconceivable to the Graeco-Roman world. Many of the Plebeians had no clans; they could not, therefore, be made members of the three primitive tribes,[268] and when the change was first mooted, it was, probably for the same reason, thought impossible to make them members of the _curiae_.[269] New tribes must be invented which should include the whole community. The chief burden of taxation, now imposed equally on all classes, was to lie on land. What more natural than that the tribes should be territorial divisions, so defined as to include all the territory held in ownership by the Roman people? It is established that the tribes, which are specially described as local,[270] contained only that land which was subject to quiritarian ownership,[271] and from this fact the deduction has been drawn that all land subject to quiritarian ownership was included in the tribes. As the Servian tribes were believed only to have comprised the city itself, as enclosed by the Servian walls,[272] this view leads to the startling conclusion that no land was held in private ownership outside the city, as its limits were fixed by Servius—that the land outside, so far as it was not _ager publicus_, was held by some larger corporation such as the _gens_.[273] But such a conclusion is most improbable; it was the evolution of private ownership which had created the rich Plebeian, who had often no clan and could not hold in common with others, and such a holder was the least likely man in the world to have land in or near the city, even as its limits were fixed by Servius. Consequently if, as seems to have been the case, the tribes did include all landowners, they must have extended far beyond the bounds of the city. Our authorities knew them at a time when their names indeed survived, but when they had become strictly divisions of the city, by the complete separation of the country from the urban tribes. If we believe in the urban character of the four original _tribus_, we must accept the clearly expressed but generally discredited belief preserved by Dionysius that besides these four tribes, which comprehended only the city, Servius established twenty-six others which took in the country districts.[274]