This is obviously a description of run-rig in a state of decrepitude; the communal spirit has died out of it, and apparently the practice of periodic redivision of the land has fallen into desuetude. In another passage[87] we find a variation of the method of guarding the crops which again, when compared with Mr. Carmichael’s description of the “promiscuous rig,” appears to show the decay of the system. “The tenants have a miserable sort of fence, made of turf, which separates their arable land from the adjoining waste; but it requires constant repairs, and when the corn is taken off the ground, is entirely neglected, and the country becomes one immense common, over which immense numbers of cattle are straggling in search of food, greatly to the injury of the soil.” [87] _Ibid._, p. 207. This passage and the next occur in the description of Caithness, but they appear to be intended to apply to the whole district. William Marshall, the rival as an agricultural writer and bitter critic of Arthur Young, supplied the “General View of the Agriculture of the Central Highlands of Scotland.” He supplies us with one significant hint, if we need it, with regard to the fundamental basis of run-rig: “Not the larger farms only, but each subdivision, though ever so minute, _whether ‘plow-gait,’ ‘half-plow,’ or ‘horse-gang,’_ has its pittance of hill and vale, and its share of each description of land, as arable, meadow, green pasture and muir” (p. 29). By the way, even smaller farms than the “horse-gang,” _i.e._, one quarter of the arable land which could be ploughed by a four-horse plough, together with the corresponding proportion of meadow, pasture and moor, were to be found on the Royal burghs where intermixed ownership was exempt from the operation of the Act of 1695. On these the smallest farms consisted of a “horse’s foot” of land, _i.e._, one sixteenth part of a “plow-gait.” Dr. James Robertson defines run-rig as “Two or three or perhaps four men yoking their horses together in one plough, and having their ridges alternately in the same field, with a bank of unploughed land between them, by way of march.”[88] [88] “Agriculture of the Southern Districts of Perth” (1794).