248 : MOSQUITOES. 
pures the Indians leave the village at night, and 
sleep on the little islands in the midst of the cata- 
racts, where the insects are less numerous. Hum- 
boldt gives an elaborate account of these creatures, 
of which, however, the most interesting particulars 
alone can be here extracted. In the missions of the 
Orinoco, when two persons meet in the morning, 
the first questions are,—“ How did you find the 
zancudoes during the night? How are we to-day 
for the mosquitoes?” The plague of these animals, 
however, is not so general in the torrid zone as is 
commonly believed. On the table-lands that have 
an elevation of more than 2558 feet, and in very 
dry plains at a distance from rivers, they are not 
more numerous than in Europe; but along the 
valleys, as well as in moist places on the coast, 
they continually harass the traveller; the lower 
stratum of air, to the height of fifteen or twenty - 
feet, being filled with a cloud of venomous in- 
sects. It is a remarkable circumstance that on the 
streams, the water of which is of a yellowish-browi 
colour, the tipulary flies do not make their ap- . 
pearance. Not less astonishing is the fact, that the 
different kinds do not associate together ; but that 
mosquitoes), says he, “do not rise high in the air, but are gene- 
rated and remain near the wet banks of the river. I found a tree 
in the neighbourhood, which I ascended nearly to its top with a 
cord. This I attached firmly to the branches, and then fixed it 
round me, so that I could not fall, but sit with safety, although not 
with much comfort. It was, however, with me here as with many 
in various situations in life—I could estimate the nature and ex- 
tent of my pleasures and my difficulties merely by comparison ; and, 
certainly, although the being tied to the top of a tree as a sleeping- 
place was not very agreeable, it was far preferable to bein ee 
swarms of hungry mosquitoes where I had previously lodged. 
enjoyed several hours’ sleep and awoke considerably refreshed.” — 
Robtinson’s Journal of an Expedition up the Orineco and Ar- 
aucda 
