The rivalry between Spain and Portugal has contributed to the poor geographical knowledge about the tributary rivers of the Amazon. The Indians are excellent geographers and can outflank the enemy despite the limits on the maps and the forts. Each side prefers to conceal what it knows, and the love of what ii mysterious, so common among ignorant people perpetuates doubt. It is also known that different Indian tribes in this labyrinth of rivers give rivers different names that all mean 'river', 'great water' and 'current'. I have often been puzzled trying to determine synonyms after examining the most intelligent Indians through an interpreter. Three or four languages are spoken in the same mission, it is hard to make witnesses agree. Our maps are full of arbitrary names. The desire to leave no void in maps in order to give them an appearance of accuracy has caused rivers to be created whose names are not synonymous. (114)