The limited region of Italy--overrun, as it repeatedly was, by hordes of barbarians during and after the times of the latest emperors--soon lost her pampered flocks; while the extended regions of Spain--intersected in every direction by almost impassable mountains--could maintain their more hardy race, in defiance of revolution or change. To what extent the improvements which have been noticed were carried is unknown; but as Spain was at that time highly civilized, and as agriculture was the favorite pursuit of the greater part of the colonists that spread over the vast territory, which then acknowledged the Roman power, it is highly probable that Columella's experiments laid the foundation for a general improvement in the Spanish sheep--an improvement, moreover, which was not lost, nor even materially impaired, during the darker ages that succeeded. The Merino race possess inbred qualities to an extent surpassed by no others. They have been improved in the general weight and evenness of their fleece, as in the celebrated flock of Rambouillet; in the uniformity and excessive fineness of the fibre, as in the Saxons; and in their form and feeding qualities, in various countries; but there has never yet been deterioration, either in quantity or quality of fleece or carcass, wherever they have been transported, if supplied with suitable food and attention. Most sheep annually shed their wool if unclipped; while the Merino retains its fleece, sometimes for five years, when allowed to remain unshorn. Conclusive evidence is thus afforded of continued breeding among themselves, by which the very constitution of the wool-producing organs beneath the skin have become permanently established; and this property is transmitted to a great extent, even among the crosses, thus marking the Merino as an ancient and peculiar race.