PHYSICAL HISTORY OF THE AMAZONS. 435 



bare on both sides of the Igarap6 Grande by the encroach- 

 ments of the ocean. That this is the work of the sea is un- 

 deniable, for all the little depressions and indentations of the 

 peat are filled with sea-sand, and a ridge. of tidal sand divides 

 it from the forest still standing behind. Nor is this all. At 

 Vigia, immediately opposite to Soure*, on the continental 

 side of the Pard River, just where it meets the sea, we have 

 the counterpart of this submerged forest. Another peat-bog, 

 with the stumps of innumerable trees standing in it, and 

 encroached upon in the same way by tidal sand, is exposed 

 here also. No doubt these forests were once all continuous, 

 and stretched across the whole basin of what is now called 

 the Para River. 



Since I have been pursuing this inquiry, I have gathered 

 much information- to the same effect from persons living on 

 the coast. It is well remembered that, twenty years ago, 

 there existed an island, more than a mile in width, to the 

 northeast of the entrance of the Bay of Vigia, which has 

 now entirely disappeared. Farther eastward, the Bay of 

 Braganza has doubled its width in the last twenty years, 

 and on the shore, within the bay, the sea has gained upon 

 the land for a distance of two hundred yards during a 

 period of only ten years. The latter fact is ascertained 

 by the position of some houses, which were two hundred 

 yards farther from the sea ten years ago than they now 

 are. From these and the like reports, from my own ob- 

 servations on this part of the Brazilian coast, from some 

 investigations made by Major Coutinho at the mouth of 

 the Amazons on its northern continental shore near Ma- 

 capa, and from the reports of Mr. St. John respecting the 

 formations in the valley of the Paranahyba, it is my belief 

 that the changes I have been describing are but a small 



