Guiana, in the larger sense of the word, is that portion of the South American continent bounded on the north and north-east by the ocean; on the south, south-west and west by the river Amazon, its tributary the Rio Negro, the river Cassiquiare, which unites the river Negro to the river Orinoco, and by the river Orinoco itself. It is thus an island; as there is no break in the water-line that surrounds it. This larger Guiana is, however, divided into two distinct portions, separated from one another by a series of mountain ranges stretching from the Orinoco to the river Oyapok. That portion, which lies between these mountain ranges and the sea, differs entirely in character from the Guiana of the watersheds of the Amazon and Orinoco. It consists of a succession of tablelands, rising one above the other, and is watered by a large number of nearly parallel rivers, whose cataracts and frequent rapids render navigation into the interior, except by canoes, practically impossible. In this Guiana, the Guiana with which this paper deals, there have never been any Spanish or Portuguese settlements. At the end of the sixteenth century no attempt had been made by the Spaniards to cross the river Orinoco, or by the Portuguese, to reach the mouth of the river Amazon. Between these two rivers lay a terra incognita, of which nothing was known, until the publication of Ralegh's Discoverie of Guiana in 1595.