358 NOTES OF A BOTANIST 
Spruce made from San Carlos before leaving for 
his great journey up the Casiquiari and Orinoco 
to Esmeralda, and up their most important tribu- 
taries the Cunucumima and the Pacimoni. It will 
be seen, by a note at the end of the next chapter, 
that the sources of the Orinoco have been reached 
by a French traveller in 1877, but nothing is yet 
gained but the bare fact of their being accessible.] 
Ascent of Piedra de Cocui 
July 19, 1853. — I started at 6 a.m. from the second 
Brazilian sitio on the left bank of the Rio Negro, 
below the mouth of a widish igarape. It took us two 
hours of ascent to reach the mouth of the narrow 
igarape which leads to the serra. It was difficult 
work pushing the canoe along this because of over- 
hanging and entangled branches of trees. Two 
hours more, herborising by the way, brought us to 
the base of the serra. The vegetation was much 
as that around the serra of Sao Gabriel : the same 
common ferns, and, on large blocks strewn at the 
base of the serra, the same delicate Selaginella grew 
on their steep faces. ... 
Much of the forest is of the loftier caatinga. 
The Cerro de Cocui is not less than 1000 feet 
above the river. The side fronting the river 
is destitute of vegetation almost to the apex, the 
rock actually overhanging its base and being 
destitute of furrow or fissure. In the concave 
part it is streaked with white, yellow, and pink, 
perhaps from decomposition of its surface, but 
there seems also to be there an unusual propor- 
tion of mica in the granite. As very little water 
