449 



mulate the tipulary insects*. The point of the 

 celebrated bifurcation of the Oroonoko has a 

 very imposing- aspect Lofty granitic moun- 

 tains rise on the northern bank ; and amid them 

 are discovered at a distance the Maraguaca and 

 the Duida. There are no mountains on the 

 left bank of the Oroonoko, west or east of the 

 bifurcation, till opposite the mouth of the Tama- 

 tama. There stands the rock Guaraco, which 

 is said to throw out flames from time to time in 

 the rainy season. When the Oroonoko is no 

 longer surrounded by mountains toward the 

 south, and reaches the opening of a valley, or 

 rather a depression of the ground, which termi- 

 nates at the Rio Negro, it divides itself into two 

 branches. The principal trunk (the Rio Para- 

 gua of the Indians) continues it's course toward 

 the west-north-west, turning round the group of 

 the mountains of Parime ; the branch which 

 forms the communication with the Amazon runs 

 into plains, the general slope of which is toward 

 the south, but of which the partial planes incline 

 in the Cassiquiare toward the south-west, and in 

 the basin of the Rio Negro toward the south- 

 east. A phenomenon so strange in appearance, 

 which I verified on the spot, merits particular 

 attention ; and so much the more, as it may 



* QreJlana has made the same observation in the Ama- 

 2K)n. (Southey, vol. i, p. 618.) 

 VOL. V. 2 o 



