The Vale of the Rio Mara,lon extends from 10° to 5° S. lat. The southern part is merely a wide ravine, but about 6° S. lat., it gradually enlarges to a valley several miles wide, and more than 200 =lea long. The southern part of this valley is probably not much more than 3000 feet above the sea-level and it lowers very gradually ; at its northern extremity, at the Ponga of Rentema, it is only 1250 feet above the sea. This valley is by far the hottest portion of the moun tain region, and the vegetation in the lower parts does not differ from that of other tropical countries. Wheat is only grown on the declivi ties of some adjacent mountains. Maize, mandioc, plantains, and yucas are most extensively grown for the consumption of the iuhabit ants, and the sugar-cane and tobacco for exportation.
On the west side of the Peruvian Andes, the regiou of the tropical productions does not ascend more than 2000 feet above the sea, but in the valleys of the mountain region it rises to between 4000 and 5000 feet, probably owing to the abundant rains which fall on the latter. The cultivated grains of this region are rice and maize, and the other products are plantains, bananas, mandioc, yams, camotes, and the eugar-cane. The principal fruits aro grapes, anouaa, pine-apples, papaws (carica), and cherimoyers. Above this region is that of the European cerealia, which towards the Pacific reaches to /0,000 feet, and in tho valleys to upwards of 12,000 feet. The grains cultivated in this region are wheat, barley, and maize ; potatoes and different kinds of pulse are also cultivated. The fruit-trees are those of Europe, among which the peach succeeds best. Above this region only guinea and barley are cultivated ; the latter for fodder. Potatoes succeed at a height exceeding 13,000 feet. There are no forest-trees on the western declivity of the Andes below 8000 or 9000 feet, but in the interior of the mountaiu region they increase in size and number in proportiou as the country declines in height, and the lowest districts are covered with nearly impenetrable forests of lofty trees.
Several roads lead from the coast of the Pacific to the interior of the mountain region. [Armes.] Six of these roads occur south of 15° 20' S. lat. The most southern is the Pass of Las Gualillas (17° 50' S. lat.), which is 14,830 feet high; the most northern moun tain pass occurs near S.10., and leads over theTaramo of Guamani, where it attains the elevation of 10,950 feet above the sea-level. The lowest and most frequented of the southern passes is that of the Altos de lox Huescos ; it runs at the foot of the volcano of Arequipa, and where it passes the Andes (16° 21' S. lat.) it is only 13,573 feet high.
Of the eastern declivity of the Andes, the portion best known is the vale of the Rio Huallaga. This extensive valley lies east of the vale of the Maranon, being separated from it by the Eastern Andes.
It extends from 10° 30' to 7° 30' S. let, about 350 miles iu length. The most southern part, as far north as 9° 30' S. lat., is narrow. In this part the descent is rapid. Huanuco is about 9000 feet above the sea-level, but at 30' S. lat. the valley is probably not more than 4000 feet high. At this place it begins to widen, the Eastern Audes receding to the distance of 15 or 20 miles from the river. About 7° S. lat. a branch of the mountains comes close up to the river, and high hilla approach also on the cast close to its banks, forming near 6° 30' S. lat. the Pongo of Huallaga, at which the valley terminates on the north. The country north of the Pongo is level, and belongs to the alluvial plain of the Amazonas. The eastern boundary of the vale is formed by a range of lofty hills. The soil of the wider portion o f the vale is chiefly alluvial, and as it combines great fertility with abundance of moisture and a great degree of heat, it is capable of main tainlog a numerous population. There are at least 100 very rainy days in tho year; rain falls at all seasons, but the most rainy season is in October and November. During the rainy season the beat is frequently oppressive. The declivities of the mountains which inclose the vale are covered with thick forests of tall trees, which is also the case with the greatest part of the vale itself. Wheat and barley are grown in the southern and more elevated districts, whence they are sent to the table-land of Pasco. In the lower part maize, plantains, and bananas are cultivated. There are also plantations of sugar-cane, coffee, cacao, and coca, a herb much used by the Indian population, who chew it with a small quantity of lime. Fruit is here produced in greater perfection than in any other part of Peru, and there are several sorts of vegetables.
The Eastern Plains. — The country to the east of the range of hills which form the eastern boundary of the vale of the Huallaga, and extending from their base to the banks of the Rio Ucayali, is known under the name of the Pampa del Sacramento. But though the term 'pampa' is applied in South America to level plains destitute of trees, this country is covered with woods. The surface also is not a level, except along the banks of the Rio Ucayali. At some distanco from this river the country is diversified by numerous eminences. This region extends from the banks of the Amazonas to the Rio Pachitea, more than 300 miles from north to south, with a breadth varying between 40 and 100 miles. North of 7° S. lat. it is a dead level, and forma part of the alluvial plain of the Amazonas. No European settlements have been established in this part of Peru. It does not suffer from oppressive heat, while in fertility and products it appears to be little inferior to the vale of Huallaga. It is still in possession of the Dative tribes, of whom a small number have embraced Christianity.