It is not until nearly three hundred kilometres have been traversed, and the train has rumbled over the long bridge that spans the Rio Negro that the first symptoms of a changing scenery become evident. The undulations have become less regular, and the hill-tops are soaring higher into the sky-line. Indeed, the tendency throughout is towards an exuberance that has been hitherto lacking. Thus not only the outbreaks of stone that scar the hill-faces at intervals are bolder in character now, but the wealth of field flowers, too, has grown in extent and brilliance. A broad, glowing bank of the purple _flor morala_ lines the railway track on either hand, pricking across the landscape in twin unbroken bands of colour. Where the loftier flower ceases, the red, white, and mauve of the verbena clings closely to the turf. At longer intervals sprout clumps of blue lupin blossom, while the white mallows, harebells, and tobacco flowers lurk thickly in between the groves of thistle, and large yellow marguerites and daisies mingle with a variegated host of blooms. The countryside is as sparsely populated as elsewhere. League upon league of the great rolling sweeps of the land spread their panorama unflecked by a single homestead. So far as the mere picturesque is concerned, the result is admirable. The soft, dreamy landscape is at its very best when unburdened by human habitation. Yet in such cases the picturesque becomes a luxury won at the expense of the practical. Undoubtedly from the green background of the pastures should shine out the white walls of estancia-houses and ranchos. The time is now probably near enough when such will actually be the case; but in the meanwhile the land waits in complacent patience, sprouting out its grassy covering with contemptuous ease. Yet it must not be imagined that the landscape, however lonely, is altogether deserted. Now and then may be discerned the clump of trees that stand out like islands from the sea to shelter the dwellings of the owners of these great areas of soil. At long intervals, too, springs up a hedge of tall cactus that flanks the humble rancho, whose tin roof, as often as not, is held down in its place by means of small boulders--a feature of architecture that recalls the châlets of Switzerland, although it is certain enough that the respective buildings have nothing else in common. Here and there graze the dumb supporters of the homesteads--herds of cattle, troops of horses, and flocks of sheep. These districts of the centre have not yet attained to the standard of breeding that characterises the lands that fringe the great rivers to the south and west. Thus, the cattle, although sufficiently fat and sleek, lack the finish of the more aristocratic Hereford. Shaggy of coat, long of horn, and exhibiting an utter lack of restraint in the strangely varied colour scheme of their bodies, they are essentially of the _criollo_, or native, order.