374 A JOURNEY IN BRAZIL. 



The only thing he may be tempted to take will be a canoe 

 and a pair of oars : with these an Indian is rich. He only 

 wants to get back to his woods ; and he is deterred by no 

 sentiment of affection, or consideration of interest. 



To-day we are passing the hills of Alnieyrim. The last 

 time we saw them it was in the glow of a brilliant sunset ; 

 to-day, ragged edges of clouds overhang them, and they aie 

 sombre under a leaden, rainy sky. It is delightful to Mr. 

 Agassiz, in returning to this locality, to find that phenomena, 

 which were a blank to him on our voyage up the river, are 

 perfectly explicable now that he has had an opportunity of 

 studying the geology of the Amazonian Valley. When we 

 passed these singular flat-topped hills before, he had no clew 

 to their structure or their age, whether granite, as they have 

 been said to be, or sandstone or limestone ; whether primi- 

 tive, secondary, or tertiary : and their strange form made the 

 problem still more difficult. Now he sees them simply as 

 the remnants of a plain which once filled the whole valley of 

 the Amazons, from the Andes to the Atlantic, from Guiana 

 to Central Brazil. Denudations on a colossal scale, hitherto 

 unknown to geologists, have turned this plain into a laby- 

 rinth of noble rivers, leaving only here and there, where the 

 formation has resisted the rush of waters, low mountains 

 and chains of hills to tell what was its thickness.* 



February ~\_st. On Tuesday evening we reached Porto do 

 Moz, on the river Xingu, where we had expected to be de- 

 tained several days, as Mr. Agassiz wished especially to 

 obtain the fishes from this river, and, if possible, from its 

 upper and lower course, between which rapids intervene. 

 He found, however, his harvest ready to his hand. Senhor 

 Vinhas, with whom, when stopping here for a few hours on 



* Sec Chapter XIII., on the Physical History of the Amazons. 



