From the chain of mountains which borders the Lake of Valencia toward the south, there stretches in the same direction a vast extent of level land, constituting the Llanos or Savannahs of Caraccas; and from the cultivated and populous district of Aragua, embellished with mountains and rivers and teeming with vegetation, one descends into a parched desolate plain, bounded by the horizon. On this route we now accompany our travellers, who on the 6th March left the valleys of Aragua, and keeping along the south-west side of the lake, passed over a rich champaign country covered with calabashes, water-melons, and plantains. The rising of the sun was announced by the howling of monkeys, of which they saw numerous bands moving as in procession from one tree to another. These creatures (the Simia ursina) execute their evolutions with singular uniformity. When the boughs of two trees do not touch each other, the leader of the party swings himself by the tail upon the nearest twigs, the rest following in regular succession. The distance to which their howlings may be heard was ascertained by Humboldt to be 1705 yards. The Indians assert that one always chants as leader of the choir; and the missionaries say that when a female is on the point of bringing forth, the howlings are suspended till the moment when the young appears.