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 baccatum), 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 musaceae 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- 
lastomaceai 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 Bio Yichada, 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 Yichada. I could learn nothing of > ts 
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 Bosalia de Cabapuna, a village situate on the 
banks of the Meta, have arrived even recently, by the B l ° 
Yichada, 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 name* 
