CHAP. XII IN HUMBOLDT'S COUNTRY 407 
these pests. If I climbed the cerros, or buried 
myself in the forest, or sought the centre of the 
savannas, it was the same, but it was worst of all on 
the river. At San Carlos they were often bad 
enough ; in ascending the Casiquiari every day 
brings an increase of mosquitoes, until, towards the 
upper mouth and out on the Orinoco, they are an 
indescribable annoyance. Many times there is no 
sitting down -to eat a meal, but one must walk 
about, platter in hand, and be content to eat one's 
food well peppered with mosquitoes. I found 
working at my plants very difficult, although I put 
on gloves and tied down my trousers over my ankles. 
The face and neck were necessarily exposed, and 
my gloves and sleeves were constantly streaked 
with blood from brushing away the little insects. 
Most of these minute flies leave a small clot of blood 
in the place where they have been sucking, and 
with me the wounds often bled considerably. 
[The Journal now continues : — ] 
Duida as seen from Esmeralda seems a cubical 
mass, one face parallel to the Orinoco and another 
to the Guapo. . . . Throughout it is forest-clad (in 
the ravines to the very summit) save where the 
rock is nearly perpendicular. The south-east angle 
seems to be micaceous schist and glitters like silver 
when the sun shines on it. Most of the rock about 
Esmeralda is schistose, and where the stones are 
placed with the lamina perpendicular they are worn 
by the action of rains and the atmosphere into 
close-set sharp edges which treat the naked feet 
very cruelly. 
The inhabitants of Esmeralda are a quite different 
race from those met by Humboldt. When it had 
