A third species of ploughing-duty is the so-called _aver-earth_ or _grass-earth_. This obligation arises when the peasants want more pasture than they are entitled to use by their customary rights of common. The lord may grant the permission to use the pasture reserved for him, and exacts ploughings in return according to the number of heads of cattle sent to the pasturage[582]. Sometimes the same imposition is levied when more cattle are sent to the commons than a holding has a right to drive on them[583]. It is not impossible that in some cases the very use of rights of common was made dependent on the performance of such duties[584]. A kindred exaction was imposed for the use of the meadows[585]. Local variations have, of course, to be taken largely into account in all such matters: the distinction between gafol-earth and grass-earth, for instance, though drawn very sharply in most cases, gets somewhat confused in others. Manorial records mention a fourth variety of ploughing-work under the name of _ben-earth_, _precariae carucarum_. This is extra work in opposition to the common ploughings described before[586]. It is assumed that the subject population is ready to help the lord for the tillage of his land, even beyond the customary duties imposed on it. It sends its ploughs three or four times a year 'out of love,' and 'for the asking.' It may be conjectured how agreeable this duty must have been in reality, and indeed by the side of its common denominations, as boon-work and asked-work, we find much rougher terms in the speech of some districts--it is deemed _unlawenearth_ and _godlesebene_[587]. It must be said, however, that the lord generally provided food on these occasions, and even went so far as to pay for such extra work. Other expressions occur in certain localities, which are sometimes difficult of explanation. _Lentenearth_[588], in the manors of Ely Minster, means evidently an extra ploughing in Lent. The same Ely records exhibit a ploughing called _Filstnerthe_ or _Filsingerthe_[589], which may be identical with the Lentenearth just mentioned: a _fastnyngseed_[590] occurs at any rate which seems connected with the ploughing under discussion. The same extra work in Lent is called _Tywe_[591] in the Custumal of Bleadon, Somersetshire. When the ploughing-work is paid for it may receive the name of _penyearth_[592]. The Gloucester survey speaks of the extra cultivation of an acre called Radacre, and the Ely surveys of an extra rood 'de Rytnesse[593].' I do not venture to suggest an explanation for these last terms; and I need not say that it would be easy to collect a much greater number of such terms in local use from the manorial records. It is sufficient for my purpose to mark the chief distinctions. [Reaping.]