Chap. L 
CONICAL HILL. 
47 
To the south my rambles never extended farther than 
the banks of the Irura, a stream which rises amongst 
the hills already spoken of, and running through a 
broad valley, wooded along the margins of the water- 
courses, falls into the Tapajos, at the head of the bay of 
Mapiri. All beyond, as before remarked, is terra incog- 
nita to the inhabitants of Santarem. The Brazilian 
settlers on the banks of the Amazons seem to have no 
taste for explorations by land, and I could find no per- 
son willing to accompany me on an excursion further 
towards the interior. Such a journey would be exceed- 
ingly difficult in this country, even if men could be 
obtained willing to undertake it. Besides, there were 
reports of a settlement of fierce runaway negroes on the 
Serra de Mururaru, and it was considered unsafe to go 
far in that direction, except with a large armed party. 
I visited the banks of the Irura and the rich woods 
accompanying it, and two other streams in the same 
neighbourhood, one called the Panema, and the other 
the Urumari, once or twice a week during the whole 
time of my residence in Santarem, and made large 
collections of their natural productions. These forest 
brooks, with their clear cold waters brawling over their 
sandy or pebbly beds through wild tropical glens, 
always had a great charm for me. The beauty of the 
moist, cool, and luxuriant glades was heightened by the 
contrast they afforded to the sterile country around 
them. The bare or scantily wooded hills which sur- 
round the valley are parched by the rays of the vertical 
sun. One of them, the Pico do Irura, forms a nearly 
perfect cone, rising from a small grassy plain to a height 
