C0XKEXI03 OF THE PLAINS. 
95 
and July, communicate with the basin of the Amazon and 
the Rio Negro, bounded on one side by the Cordillera ot 
Chiquitos, and on the other by the mountains of Panme. 
The opening which is left between the latter and the 
Andes of New Grenada, occasions this communication. The 
aspect of the country here reminds us, but on a much 
larger scale, of the plains of Lombardv. which also are only 
fifty or sixty toises above the level o zx ocean ; and are 
directed first from La Brenta to Turin, east and west ; and 
then from Turin to Coni, north and south. If we were 
authorized, from other geological facts, to regard the three 
great plains of the Lower Orinoco, the Amazon, and the 
ltio de la Plata as basins of ancient lakes,* we should 
imagine we perceived in the plains of the Rio Vichada and 
the Meta, a channel by which the waters of the upper 
lake (those of the plains of the Amazon) forced their way 
towards the lower basin, (that of the Llanos of Caracas,} 
separating the Cordillera of La Parime from that of the 
Andes. This channel is a land of land-strait. The ground, 
which is perfectly level between the Guaviare, the Meta^ 
and the Apure, displays no vestige of a violent irruption of 
the waters ; but on the edge of the Cordillera ot Parime, 
between the latitudes of 4° and 7°, the Orinoco, flowing in 
a westerly direction from its source to tho mouth ot the 
Guaviare, has forced its way through the rocks, directing 
its course from south to north. All the great cataracts, as 
we shall soon see, are within the latitudes just named. 
When the river has reached the mouth of the Apure in that 
\ ery low ground where the slope towards the north is met 
by the counter-slope towards the south-east, that is to say, 
by the inclination of the plains which rise imperceptibly 
towards the mountains of Caracas, the river turns anew and 
flows eastward. It appeared to me, that it was proper to 
fix the attention of the reader on these singular inflexions 
of the Orinoco because, belonging at once to two basins, its 
course marks, in some sort, even on the most imperfect 
maps, the direction of that part of the plains intervening 
* In Siberia, the great steppes between the Irtish and the Obi, espe- 
cially that of LSaraba, full of salt lakes (Tchabakly, Tchany, Karasouk, 
and Topolony), appear to have been, according to the Chinese tradition^ 
even within historical times, an inland sea. 
