248 A JOURNEY IN BRAZIL. 
interfered very seriously with our comfort. There is a 
tiny creature called the Mocuim, scarcely visible except 
for its bright vermilion color, which swarms all over the 
grass and low growth here. It penetrates under the skin 
so that one would suppose a red rash had broken out over 
the body, and causes excessive itching, ending sometimes 
in troublesome sores. On returning from a walk it is 
necessary to bathe in alcohol and water, in order to allay 
the heat and irritation produced by these little wretches. 
Mosquitoes are annoying, piums are vexatious, but for 
concentrated misery commend me to the Mocuim. 
October 23d. We left Teffe on Saturday evening on 
board the Icamiaba, which now seems quite like a home 
to us ; we have passed so many pleasant hours in her 
comfortable quarters since we left Para. We are just 
on the verge of the rainy season here, and almost every 
evening during the past week has brought a thunder-storm. 
The evening before leaving Teffe we had one of the most 
beautiful storms we have seen on the Amazons. It came 
sweeping up from the east ; these squalls always come 
from the east, and therefore the Indians say " the path of 
the sun is the path of the storm." The upper, lighter 
layer of cloud, travelling faster than the dark, lurid mass 
below, hung over it with its white, fleecy edge, like an 
avalanche of snow just about to fall. We were all sitting 
at the doorstep watching its swift approach, and Mr. Agassiz 
said that this tropical storm was the most accurate represen- 
tation of an avalanche on the upper Alps he had ever seen. 
It seems sometimes as if Nature played upon herself, repro- 
ducing the same appearances under the most dissimilar 
circumstances. It is curious to mark the change in the 
river. When we reached Teffe it was rapidly falling at 
