284 Through the BraziHan Wilderness 



While our course as a whole had been almost due 

 north, and sometimes east of north, yet where there were 

 rapids the river had generally, although not always, 

 turned westward. This seemed to indicate that to the 

 east of us there was a low northward projection of the 

 central plateau across which we had travelled on mule- 

 back. This is the kind of projection that appears on 

 the maps of this region as a sierra. Probably it sent low 

 spurs to the west, and the farthest points of these spurs 

 now and then caused rapids in our course ( for the rapids 

 generally came where there were hills) and for the mo- 

 ment deflected the river westward from its general down- 

 hill trend to the north. There was no longer any ques- 

 tion that the Diivida was a big river, a river of real 

 importance. It was not a minor affluent of some other 

 affluent. But we were still wholly in the dark as to 

 where it came out. It was still possible, although ex- 

 ceedingly improbable, that it entered the Gy-Parana, as 

 another river of substantially the same size, near its 

 mouth. It was much more likely, but not probable, that 

 it entered the Tapajos. It was probable, although far 

 from certain, that it entered the Madeira low down, near 

 its point of junction with the Amazon. In this event it 

 was likely, although again far from certain, that its mouth 

 would prove to be the Aripuanan. The Aripuanan does 

 not appear on the maps as a river of any size ; on a good 

 standard map of South America which I had with me its 

 name does not appear at all, although a dotted indication 

 of a small river or creek at about the right place prob- 

 ably represents it. Nevertheless, from the report of one 

 of his lieutenants who had examined its mouth, and from 



