THE CHIRIVA
PALM-TREE.
409
m o u n t a i n s ? * o r have these walls o f r o c k , these turrets o f granite, been upheaved b y the elastic forces that still act in the interior o f o u r planet ? W e m a y b e permitted t o m e d i tate a little o n the origin o f mountains, after having seen the position o f the M e x i c a n volcanos, and o f trachyte summits o n an elongated c r e v i c e ; having f o u n d in t h e A n d e s o f South A m e r i c a primitive and volcanic rocks in a straight line in the same c h a i n ; and when w e recollect t h e island, three miles in circumference, and o f a great height, which in m o d e r n times issued from the depths o f the ocean near Oonalaska. T h e banks o f the Cassiquiare are adorned with t h e chiriva palm-tree with pinnate leaves, silvery o n the u n d e r part. T h e rest o f t h e forest furnishes only trees with large, coriaceous, glossy leaves, that have plain edges. This peculiar p h y s i o g n o m y † o f the vegetation o f t h e Guainia, the Tuamini, and the Cassiquiare, is o w i n g t o t h e preponderance o f the families o f the guttiferæ, the sapotæ, and the laurineæ, in the equatorial regions. T h e serenity o f the sky p r o m i s i n g us a line night, we resolved, at five in the evening, t o rest near t h e Piedra de Culimacari, a solitary granite r o c k , like all t h o s e which I have described b e t w e e n t h e A t a b a p o and the Cassiquiare. W e found b y the bearings o f the sinuosities o f t h e river, that this rock is nearly in the latitude o f the mission o f San Francisco Solano. I n those desert countries, w h e r e man has hitherto left only fugitive traces o f his existence, I constantly endeavoured t o make m y observations near t h e m o u t h o f a river, o r at the foot o f a r o c k distinguishable b y its f o r m . Such points o n l y as are immutable b y their nature can serve for the basis o f geographical maps. I obtained, in the n i g h t o f the 10th o f M a y , a g o o d observat i o n o f latitude b y a o f t h e S o u t h e r n C r o s s ; t h e l o n g i t u d e was determined, but with less precision, b y t h e c h r o n o m e t e r , * The Sierra de la Parime, or of the Upper Orinoco, and the Sierra (or Campos) dos Parecis, are part of the mountains of Matto Grosso, and form the northern back of the Sierra de Chiquitos. I here name the two chains of mountains running from east to west, and bordering the plains or basins of the Cassiquiare, the Rio Negro, and the Amazon, between 5° 30' north, and 14° south latitude. † This physiognomy struck us forcibly, in the vast forests of Spanish Guiana, only between the second and third degrees of north latitudes.