BRANNER: THE STONE REEFS OF BRAZIL. 129 



The accompanying plate (5), made from the beautiful topographic sheet 

 just issued by tlie Commissao Geographica e Geologica de Sao Paulo under 

 Prof. 0. A. Derby, shows the general features of that interesting region. 



The Serra do Mar, from an elevation of over one thousand metres, 

 here slopes abi'uptly beneath the flat mangrove swamps that lie along 

 its base in the neighborhood of Santos. These swamps, cut here and 

 there by winding tide streams, extend up and down the coast, but ai-e 

 interrupted now and then by headlands — like that at Guaruja — that 

 are really mountain spurs extending down to the sea. 



The hills over the plains about Santos are mostly mountain-tops pro- 

 truding from the mud and sands that have accumulated in the original 

 bay since the depression took place. Morro do Taipii, Ponta de Itaipii, 

 Morro do Xixova, and Morro Jtarare were all originally the crest of a 

 ridge that continued past Barnabe Island in the direction of Pico Jacoa- 

 reguava, while Ponta Manduba was the crest of another ridge passing 

 Guaruja in the same direction. The hills south of the Praia de Per- 

 nambuco were the crest of another of these parallel ridges. 



A striking thing about the ports of Brazil is that the small ones have 

 all been choked up by coast debris, and only the two big ones, Bahia 

 and Eio de Janeiro, have been able, on account of the depths of their 

 mouths and the consequent scour of the tides, to keep their basins open. 

 But even these large ones are filling in from their upper ends, a process 

 greatly hastened on the coast of Brazil by the gx'owth and encroachment 

 of mangrove plants. 



Coast lakes. — Lakes may be formed along a coast by an elevation 

 bringing up closed basins — accidental foi'ms of the sea floor,^ or they 

 may be caused by a depression of troughs, valleys, or shallow-mouthed 

 estuaries whose ends become closed in time by shore accretions, however 

 made, but generally the result of the destructive and constructive work 

 of the sea. The strong winds and currents that set against the Brazilian 

 coast the whole year round make the contest between land forces and 

 sea forces an unequal one ; the sea is aggressive and always gaining. 

 The headlands are cut away and their remains thrown into every in- 

 dentation of the coast, damming in rivers and obliging them sometimes to 

 wander for kilometres behind huge spits before they can escape to the sea. 



If, with these two methods of lake-forming in mind, we attempt to 

 get at the history of the Brazilian coast lakes, we find that information 

 regarding their surroundings is too meagre in most cases to enable us to 



1 Such as are apparently meant by Capanema. Petermann's Mittheihmgen, 1874, 

 p. 230. 



