protection, those instincts, which can be subdued but not eradicated, are brought into operation, and their presence will go far to retard the advancement of those qualities, on the perfection of which a profit can alone be hoped for. [13] Edin. Philosophical Journal. (78.) _Breeds required for Britain._--Of the numerous breeds at present in our island, a few only are indispensably necessary for the continuance of its prosperity. These stand, according to Marshall, thus:--A very long-woolled sheep, as the Lincolnshire, or Teeswater, for the richest grass lands, and finest worsted manufactures--the New Leicester, for less fertile grass land, and for rich enclosed arable land, on which the fold is not used; intended to supply coarser worsted, stockings, coarse cloths, blankets, and carpets--a middle-woolled breed, as the Wiltshire, the Norfolk, or the Southdown, for arable lands on which folding is practised, and for cloths of middle qualities--a fine-woolled, as the Ryeland, for the finest cloths; and a hardy race for heathy mountains. Some argue, and rightly, that only three breeds are necessary for Scotland, inasmuch as only three are required by the nature of the country. Scotland may be regarded, in an agricultural point of view, as divided into highland, upland, and plain. The highland consists of primitive rocks, covered by peaty soil and heath, on which these indefatigable gleaners, the black-faced sheep, alone can gain a subsistence. The upland is formed by the transition series of rocks, covered with grass; and to it the Cheviots appear indigenous. The plain is formed by alluvial deposits, covered with rich pasture, and capable of supporting races of large sheep, as the Leicesters. Sheep are the only kind of live-stock which ought to be kept in mountainous districts, especially when green crop cannot be cultivated. Sheep-farming must necessarily prevail in the Highlands, where there are few tracts suited for the pasturage of black cattle: The value of its adaptation to the natural circumstances of that district is proved by the rapid progress which it made, and the profits which resulted to the individuals with whom it originated. Places which formerly were not of the slightest utility, now yielded heavy rents. The spots among the mountains, susceptible of cultivation, were found to be advantageously kept in grass, to serve as pasture for the flock during the rigour of winter, and it was well ascertained that more than double rent might be paid by stocking with sheep in preference to cattle.