=Highlands.= The physical features of the country are simple, the Paraguay River dividing it into sections: the Gran Chaco, to some extent unexplored in detail, and the Oriental. The latter, Paraguay proper, is traversed from north to south by a broad irregular belt of highlands, nowhere much above 2200 feet. The angle of the ridges is sharper on the west, the country undulating in gradual slopes from the foot. On the east, spurs run out enclosing deep valleys, and the country has more of an upland character. The streams flowing west to the Paraguay are smoother and to some extent navigable, while those flowing east and southeast to the Alto Paraná are interrupted by rapids and falls. =Plains.= In the southwest section between the Paraguay and the Paraná there is considerable marshy country, part draining into the Ypoa lagoon; other marshy lowlands occur along the Paraguay River. All these could be drained at moderate expense, thus providing much rich and accessible land. The western section, containing most of the inhabitants, has an average altitude of about 600 feet. In the more settled parts of the west and south are extensive grassy and open lands, and hills covered with forests, while clumps of trees are frequent in the lowlands. The soil of the western part is rather dry and sandy except near the rivers and marshes. It is extremely rich, of a reddish color due to impregnated iron. Above is a thick layer of humus, formed by centuries of decaying vegetation. In places the soil is clayey, or has a substratum of clay beneath. This is true of most of the forest region, and of the swampy section. Of Paraguay proper the western part is 25 per cent forest, the middle 66, the eastern 95 per cent. The Gran Chaco, though called a plain, and flat near the rivers, is somewhat hilly. Rarely, a freshet on the Paraguay or the Pilcomayo transforms the neighboring country into great lakes, these sometimes extending 20 or 30 miles back from the river. Along the river banks is usually a narrow strip of forest, from which the soil and trees occasionally crumble into the stream, especially along the Pilcomayo, thus impeding navigation on that river. Farther back are open plains dotted with groups of palms, and some stretches of forest. The average altitude is 426 feet. Little is known of the country north of 22°.