1879.] Artificial Mounds of the Island of Marajó, Brasil. 225 
cattle are drowned in the lowlands, or fall victims to the alliga- 
tors, and, from time to time, a more severe winter than usual de- 
prives them of fodder, and occasions severe losses. Another and 
more important inconvenience arises from the impossibility of re- 
taining in good condition a sufficient number of horses for farm 
work. Formerly horses thrived so well on the island that they 
came to take entire possession of the grazing grounds, forming a. 
serious impediment to the industry of cattle-raising, and about 
forty years ago the farmers killed them by thousands for the sake 
of their hides. To-day horses are so expensive and their preser- 
vation so difficult that they are only in use where it is absolutely 
impossible to dispense with them. For ordinary service, and even 
for traveling, oxen are used, and, upon one occasion, I witnessed 
a troop of horses being driven to their enclosure by herdsmen 
mounted on oxen. 
Near the centre of the island, in the midst of the plains, is a 
lake called Arary, out of which flows a river bearing the same 
name. Other important rivers are, the Igarapé-grande, which 
empties at the south-east part of the island, and the Anajús, which 
rises a little to the west of lake Arary, and, crossing the forests 
of the western side, receives, before leaving the plains, the tribu- 
taries Camutins and Moções. On the margins of all these rivers 
artificial mounds exist, but only those of lake Arary and the Ca- 
mutins have been examined. Those which I shall now describe 
may be taken as types. 
The best known mound is situated by the side of lake Arary, 
and in the winter becomes transformed into an island called the 
Island of Pacoval. In shape it is nearly oval, having a length of 
one hundred and fifty metres, a breadth of seventy metres, and a 
height of five metres above the water of the winter’s overflow, 
which covers all the neighborhood for many miles around. 
On one side of the island, exposed to the action of the waves, 
is a small cliff, in which the structure of the mound is displayed, 
and where it is seen that even to its base the earth is filled with 
pottery and ashes, proving the artificial origin of the mound. 
The waves have excavated very extensively into it, and the beach 
below is covered with the fragments of pottery. The mound 
being thickly wooded, the objects lying near the surface have 
been much broken up by the roots of the trees, but at-a greater 
depth they are preserved in perfect condition. Several other lo- 
VOL. XI11.—No, IV. 16 
