282 
MIGRATIONS or THE MOSQUITOS. 
intervals. In places where the absence of crocodiles permit* 
people to enter a river, M. Bonpland and myself observed 
that the immoderate use of baths, while it moderated the 
pain of old stings of zancudos, rendered us more sensible 
to new stings. By bathing more than twice a day, the skin 
is brought into a' state of nervous irritability, of which no 
idea can be formed in Europe. It would seem as if all 
feeline were carried toward the integuments. 
As the mosquito® and gnats pass two-thirds of their lives 
in the water, it is not surprising that these noxious insects 
become less numerous in proportion as you recede from the 
banks of the great rivers which intersect the forests. They 
seem to prefer the spots where their metamorphosis tooK 
place, and where they go to deposit their eggs. In tact the 
wild Indians (Indios monteros) experience the greater din 1 ' 
culty in accustoming themselves to the life ot the missions, 
as they sutler in the Christian establishments a tormeu 
which they scarcely know in their own inland dwellings 
The natives at Maypures, Atures, and Esmeralda, have bee' 1 
seen fleeing to the woods, or, as they say, o.l monte,, solely 
from the dread of mosquitos. Unfortunately, all the Mission* 
of the Orinoco have been established too near the banks o‘ 
the river. At Esmeralda the inhabitants assured us that n 
the village were situated in one of the five plains surrounding 
the high mountains of Duida and Maraguaea, they should 
breathe freely, and enjoy some repose. The great cloud 
mosquitos (la nube de moscas) to use the expression of t 
monks, is suspended only over the Orinoco and its tributary 
streams, and is dissipated in proportion as you remove 
the rivers. We should form a very inaccurate idea 
Guiana and Brazil, were we to judge ot that great forest to 
hundred leagues wide, lying between the sources ot 1 
Madeira and the Lower Orinoco, from the vallies ot ti 
rivers by which it is crossed. 
1 learned that the little insects of the family of the nem^ 
cer® migrate from time to time like the alouate monkey^ 
which live in society. In certain spots, at the comment ' 
ment of the rainy season, different species appear, the stujjo 
of which has not yet been felt. We were informed at 11 
Eio Magdalena, that at Sirniti no other culex than the J<U * 
was formerly known ; and it was then possible to enjQ.V 
