2 A NATURALIST IN BRAZIL. 
thence seaward the bottom slopes rapidly down beneath the 
almost unfathomable depths of the ocean. ‘The walls of the 
continent do not arise perpendicularly from the ocean floor ; 
they slope, to give greater strength and stability to the 
structure. As a general rule we know that the water which 
borders a low coast is shallow for some distance out, the 
sea-bottom continuing under water with the same general 
slope as the land. New Jersey is a State whose coast-lands 
are low and flat, and we find that the sea-bottom bordering 
it grows very gradually deeper and deeper, in such a way 
that the true edge of the continent, or of the ocean, properly 
speaking, lies at a distance of about eighty miles from the 
land. Just such a submerged border runs along the coast of 
Brazil, in some places being many miles in width, in others 
reduced to a very narrow strip; and we find the general rule 
holds good here as elsewhere, that the deeper water along _ 
the coast lies off the highest hills, while the flat lands are 
bordered by shallow water. 
Professor Agassiz, in one of his New York lectures last 
winter,* showed how very strikingly alike North and South 
America are in their general and physical features. Not 
only is this true, but an examination of the eastern coasts of 
Brazil and the United States will show that there is a won- 
derful resemblance in the details of their geological struc- 
ture. Thus, running all along the eastern coast of the Uni- 
ted States, we find a range of mountains in which some of 
the oldest stratified rocks are upheaved, and on the eastern 
flank of these mountains, south of New York, are low lands 
occupied by more recent formations, thick beds of sandstone 
of the Triassic age and beds of marls, ete., of the Creta- 
ceous; and over these, again, deposits of Tertiary and re- 
cent times. 
I take a big Webster’s dictionary, open it a little and 


* Cooper Institute, February 5, 1867. In his lately publist B 
“fessor Agassiz has carried out this comparison between the two Americas to a much 




