53 



The prote;icese # , crotons, agaves, and the 

 great tribe of the cactuses, which inhabit exclu- 

 sively the New World, disappear gradually, as 

 you ascend the Oroonoko above the mouths of 

 the Apure and the Meta. It is rather the shade 

 and humidity, however, than the distance from 

 the coast, which oppose the migration of the 

 cactuses toward the south. We found real fo- 

 rests of them mingled with crotons, covering a 

 great space of arid land to the east of the An- 

 des, in the province of Bracamoros, toward the 

 Upper Maragnon. The arborescent ferns seem 

 to fail entirely near the cataracts of the Oroono- 

 ko ; we found no species as far as San Fernan- 

 do de Atabapo, that is, to the confluence of the 

 Oroonoko and the Guaviare. 



Having now examined the vicinity of the 

 Atures, it remains for me to speak of the rapids 

 themselves, which are found in a part of the 

 valley, where the bed of the river, deeply in- 

 gulfed, has almost inaccessible banks. It was 

 only in a very few spots, that we could enter 

 into the Oroonoko to bathe between two cata- 

 racts, in coves, where the waters have eddies of 

 little velocity. Persons who have dwelt in the 

 Alps, the Pyrenees, or even the Cordilleras, so 

 celebrated for the fractures and the vestiges of 



* Rhopalas, which characterise the vegetation of the Lla- 

 nos. 



