We need not dwell much on the observation that the servile tenements sometimes display no perfect regularity. Sometimes the burdens incumbent on them are not quite equal. Sometimes again the holdings themselves are not quite equal. In Fulborne, Cambridgeshire, e.g., the villains of Alan de la Zuche are assessed very irregularly[736], although their tenements are described as virgates and half-virgates. Of course, the general character of the virgate system remains unaltered by these exceptional deviations, which may be easily explained by the consideration that the social order was undergoing a process of change. The disruption of some of the villain holdings and the modification of certain duties are perhaps less strange than the fact that such alterations should be so decidedly exceptional. Still, the occurrence of irregularities even within the range of villainage warns us not to be too hasty in our inferences about free tenements; it shows, at any rate, that irregularities may well arise even where there has once been a definite plan, and that it is worth while to enquire whether some traces of such an original plan may not still be discovered amidst the apparent disorder of free tenements. [Free virgates.] And a little attention will show us many cases in which free tenements are arranged on the virgate system. There is hardly any need for quotations on this point: the Hundred Rolls of all the six counties of which we possess surveys, supply an unlimited number of instances. True, fundamental divisions of land and service may often be obscured and confused by the existence of plots which do not fit into the system; but as in the case of servile tenements we occasionally find irregularities, so in the case of free tenements we often see that below the superficial irregularities there lie traces of an ancient plan. The manor of Ayllington (Elton), Huntingdonshire, belonging to the Abbey of Ramsey, presents a good example in point[737]. It is reckoned to contain thirteen hides and a half, each hide comprising six virgates, and each virgate twenty-four acres. The actual distribution of the holdings squares to a fraction with this computation, if we take into the reckoning the demesne, the free and the villain tenements. Three hides are in the lord's hand, one is held by a large tenant, John of Ayllington, eleven virgates and a half by other freeholders, forty-two virgates and a half by the villains; the grand total being exactly thirteen hides. The numerous cotters are not taken into account, and evidently left 'outside the hides' (extra hidam); this is a very common thing in the Surveys. If we neglect them, and turn to the holdings in the 'hidated' portion of the manor, we shall notice that the greater part of the free tenements are arranged on the same system as the servile tenements. We find six free tenants with a virgate apiece, one with half a virgate, three with a virgate and a half, and three jointly possessed of two virgates.