4. Beyond the lucerne belt, at the point where the plain rises toward the Sierra de San Luis and the Sierra de Cordoba, the subterranean water sinks deeper. This zone at the foot of the ranges, unsuitable for lucerne, yet with a soil comparatively rich in humus, has been taken up by agricultural workers. The wheat area extends, in the San Luis province, as far as Fraga and Naschel, in the Conlara depression. The maize area extends to Oncativo, in the Cordoba province, between the Tercero and Secundo rivers, where the summer rainfall is heavier. Thanks to the nearness of the mountains, this area has a water-supply for irrigation, and this sustains several small centres of good farms. 5. The south of the Buenos Aires province and the central Pampa are the wheat zone. The bed of _tosca_, which is not far below the soil, does no harm to the wheat except in years of drought. The valleys, where the _tosca_ is interrupted, and the dunes, where the soil is deep, are very carefully used for lucerne fields of limited extent. Wheat-growing seems now, both in this and the preceding zone, to have reached its limit, as the dryness makes it improbable that there will be any extension westward. 6. Lastly, the east of the Buenos Aires province, the centre of which is fairly indicated by the little town of Dolores, is the only part of the Pampean plain which has not been reached by agricultural colonization. The land lies low, and is badly drained. The only change that has taken place in the vegetation is a progressive improvement due to the hoofs of the cattle during their long stays there. This pastoral area is clearly limited in the south by the Sierra de Tandil. In the north it is continued in the more varied region that lies between Buenos Aires and the lower Salado, where the alternation of winter pasture on the dry lands and summer pasture in the valleys, encourages the best methods of breeding, and has made it the region of the dairy industry. In the Entre Rios province the limit of the large estates of wheat and flax is marked by 32 deg. S. lat. The part of Entre Rios which extends north of 32 deg. and the Corrientes province do not strictly belong to the Pampean region. * * * * * Extensive breeding was the first form taken by white colonization on the Pampa. The word breeding is, in fact, hardly the correct name for an industry that mainly consisted of hunting, and was wholly distinct from the patient and advanced methods used at the same time in the northern provinces.