320 AMERICAN POISONS. 



of the Silla of Caracas, the quereme, the pancratium, and 

 so many majestic liliaceous plants, cannot be considered as 

 destitute of aromatics. Besides, a dry air favours the deve- 

 lopment of the aromatic or exciting properties, only in cer- 

 tain species of plants. The most inveterate poisons are 

 produced in the most humid zone of America ; and it is 

 precisely under the influence of the long rains of the tropics, 

 that the American pimento, (Capsicum baccaturn), the 

 fruit of which is of often as caustic and fiery as In- 

 dian pepper, vegetates best. From all these considerations 

 it follows, 1st, that the New Continent possesses spices, 

 aromatics, and very active vegetable poisons, peculiar to 

 itself, and differing specifically from those of the Old World ; 

 2ndly, that the primitive distribution of species in the torrid 

 zone cannot be explained by the influence of climate solely, 

 or by the distribution of temperature, which we observe in 

 the present state of our planet ; but that this difference of 

 climates leads us to perceive why a given type of organization 

 developes itself more vigorously in such or such local cir- 

 cumstances. We can conceive that a small number of the 

 families of plants, for instance the musacea} and the palms, 

 cannot belong to very cold regions, on account of their 

 internal structure, and the importance of certain organs ; 

 but we cannot explain why no one of the family of the Me- 

 lastomacese vegetates north of the parallel of the thirtieth 

 degree of latitude, or why no rose-tree belongs to the southern 

 hemisphere. Analogy of climates is often found in the two 

 continents, without identity of productions. 



The Rio Vichada, which has a small raudal at its conflu- 

 ence with the Orinoco, appeared to me, next to the Meta 

 and the Guaviare, to be the most considerable river coming 

 from the west. During the last forty years no European 

 has navigated the Vichada. I could learn nothing of its 

 sources ; they rise. I believe, with those of the Tomo, in the 

 plains that extend to the south of Casimena. Fugitive In- 

 dians of Santa Rosalia de Cabapuna, a village situate on the 

 banks of the Meta, have arrived even recently, by the Rio 

 Vichada,- at the cataract of Maypures ; which sufficiently 

 proves that the sources of this river are not very distant 

 from the Meta. Father Gumilla has preserved the namei 





