and spring-field of the three courses rotation, or in the arable and fallow of the two courses. In the first of these eventualities, the third reserved for pasture and rest would be left out of the reckoning; it would be treated as an appurtenance of the land that was in cultivation. Cases in which the portions in the several fields are unequal seem to point to the second sense[462]. It was impossible to divide the whole territory under cultivation like a piece of paper: conformation of the soil had, of course, much to do with the shape of the furlongs and their distribution, and the courses of the husbandry could not impress themselves on it without some inequalities and stray remnants. It may happen for this reason that a man holds sixteen acres in one field and fourteen in the other. There is almost always, however, a certain correspondence between the number of acres in each field; instances of very great disparity are rare, and suppose some local and special reasons which we cannot trace. Such disparities seem to point, however, to a rotation according to two courses, because the fallow of the three courses could have been left out of the reckoning only if all the parts in the fields were equal[463]. I think that a careful inspection of the surveys from this point of view may lead to the conclusion that the two courses rotation was very extensively spread in England in the thirteenth century. [Compulsory rotation of crops.] A most important feature of the mediaeval system of tillage was its compulsory character. The several tenants, even when freeholders, could not manage their plots at their own choice[464]. The entire soil of the township formed one whole in this respect, and was subjected to the management of the entire village. The superior right of the community found expression in the fact that the fields were open to common use as pasture after the harvest, as well as in the regulation of the modes of farming and order of tillage by the township. Even the lord himself had to conform to the customs and rules set up by the community, and attempts to break through them, although they become frequent enough at the close of the thirteenth century, and especially in the fourteenth, are met by a resistance which sometimes actually leads to litigation[465]. The freeholders alone have access to the courts, but in practice the entire body of the tenantry is equally concerned. The passage towards more efficient modes of cultivation was very much obstructed by these customary rules as to rotation of crops, which flow not from the will and interest of single owners, but from the decision of communities. [Intermixture of strips.]