FROM MANAOS to TARAPOTO 25 
Negro and Casiquiari, while I only saw in one or 
two places scraps of a Selaginella — a genus which 
is represented by several beautiful species growing 
in great quantity about the falls of the Uaupes. 
Night came on immediately after we had passed 
the first fall. We slept on a sandbank shaded by 
overhanging trees, which did not prevent our 
feeling the strong and cool south wind which blew 
all night. Our men worked well in the morning, 
and by 10 o'clock we had got the cargo carried 
safely up above the last fall, and we then set on 
to cook our breakfasts with light hearts. Into all 
the falls there enters a stream of clear cool water 
tumbling down among mossy rocks, in the first and 
last fall from the left, and in the second from the 
right. In all these falls stones which have 12 
feet or more of water over them in flood are often 
coated by a black varnish, as in the cataracts of the 
Orinoco, but those higher up the slope, and there- 
fore under water for a shorter period, rarely show 
this peculiarity. 
Above Estero-yacu (the highest fall), the 
Huallaga is again broader and stiller, though 
running rapidly at points ; the mountains recede 
from the river-margin, and the vegetation puts on 
the same aspect as below the pongo. About an 
hour more brought us opposite Chapaja, an Indian 
village of a few scattered huts, whence there is a 
track leading to Tarapoto, occupying about three 
hours with mules. Another hour and we had 
entered the mouth of the Mayo, a somewhat 
smaller stream than the Huallaga, which it quite 
resembled. Here were banks of mud and sand, 
sometimes covered w^ith pebbles, as on the Huallaga 
