At this point, near the mouth of the Apure, the stream leaves the granitic chain, and flowing eastward, separates as far as the Atlantic, the impenetrable forests of Guiana from the Savannahs, on whose far distant horizon the vault of heaven seems to rest. Thus the Orinoco surrounds on the south, west, and north, the high mountain chain of the Parime, which occupies the vast space between the sources of the Jao and of the Caura. No cliffs or rapids obstruct the course of the river from Carichana to its mouth, excepting, indeed, the “Hell’s Mouth” (Boca del Inferno) near Muitaco, a whirlpool occasioned by rocks, as at Atures and Maypures, which does not, however, block up the whole breadth of the stream. In this district, which is contiguous to the sea, the only dangers encountered by the boatmen arise from the natural timber-floats, against which canoes are often wrecked at night. These floats consist of forest trees which have been uprooted and torn away from the banks by the rising of the waters. They are covered, like meadows, with blooming water-plants, and remind us of the floating gardens of the Mexican lakes. After this brief glance at the course of the Orinoco and its general features, I pass to the waterfalls of Maypures and Atures. From the high mountain-group of Cunavami, between the sources of the rivers Sipapo and Ventuari, a granite ridge projects to the far west towards the mountain of Uniama. From this ridge descend four streams, which mark, as it were, the limits of the cataracts of Maypures; two bound Sipapo and Sanariapo, on the eastern shore of the Orinoco; and two the Cameji and Toparo, on the western side. At the site of the missionary village of Maypures the mountains form a wide bay opening towards the south-west. Here the stream rushes foaming down the eastern declivity of the mountain, while far to the west traces remain of the ancient and now forsaken bank of the river. An extensive Savannah stretches between the two chains of hills, at an elevation of scarcely 30 feet above the upper water-level of the river, and here the Jesuits have erected a small church formed of the trunks of palms. The geognostical aspect of this region, the insular form of the rocks of Keri and Oco, the cavities worn in the former by the current, and which are situated at exactly the same level as those in the opposite island of Uivitari; all these indications tend to prove that the Orinoco once filled the whole of this now dried-up bay. It is probable that the waters formed a wide lake, as long as the northern dam withstood their passage. When this barrier gave way, the Savannah now inhabited by the Guareke Indians emerged as an island. The river may perhaps long after this have continued to surround the rocks of Keri and Oco, which now picturesquely project, like castellated fortresses, from its ancient bed. After the gradual diminution of the waters, the river withdrew wholly to the eastern side of the mountain chain.