362 A JOURNEY IN BRAZIL. 
house of Senlior Manuel. Mr. Agassiz and Mr. Coutinho 
have gone on a geologizing excursion to the Serra d'Erere, 
that picturesque range of hills bounding the campos, or 
open sandy plain, to the northwest of the town. They took 
different routes, Major Coutinho, with Captain Faria and one 
or two other friends, crossing the campos on horseback, 
while Mr. Agassiz went by canoe. They will meet at the 
foot of the Serra, and pass two or three days in that neigh- 
borhood. Little is as yet known of the geological structure 
of the Amazonian Serras, those of Santarem, of Monte 
Alegre, and of Almeyrim. Generally they have been con- 
sidered as prolongations either of the table-land of Guiana 
on the north, or that of Brazil on the south. Mr. Agassiz 
believes them to be independent of both, and more directly 
connected with the formation of the Amazonian Valley itself. 
The solution of this question is his special object, while 
Major Coutinho has taken barometers to determine the 
height of the range. In the mean time, I am passing a few 
quiet days here, learning to be more familiar with the scen- 
ery of a region very justly called one of the most picturesque 
on the borders of the Amazons. Not only are the views ex- 
tensive, but the friable nature of the soil, so easily decom- 
posed, combined with the heavy rains, has led to the forma- 
tion of a variety of picturesque dells and hollows, some of 
which have springs running into them, surrounded by rocky 
banks and overhung with trees. One of these is especially 
pretty ; the excavation is large, and has the form of an am- 
phitheatre ; its rocky walls are crowned with large forest- 
trees, palms, mimosas, etc., making a deep shade ; and a,t 
one side the spring flows down from the top of the cliff, with 
a pleasant ripple. Here the negro or Indian servants come 
to fill their water-jars. They often have with them the chil- 
