THE AMAZON VALLEY. 
433 
41° 30' W., drawn due west towards Guayaquil, will cut 
the boundary of the great forest in long. 78° 30', and, 
for the whole distance of about 2600 miles, will have 
passed through the centre of it, dividing it into two 
nearly equal portions. 
Por the first thousand miles, or as far as long. 56° W., 
the width of the forest from north to south is about four 
hundred miles ; it then stretches out both to the north and 
south, so that in long. 67° W. it extends from 7°N., 
on the banks of the Orinooko, to 18° S., on the northern 
slope of the Andes of Bolivia, a distance of more than 
seventeen hundred miles. From a point about sixty 
miles south-east of Tabatinga, a circle may be drawn of 
1100 miles in diameter, the whole area of which will be 
virgin forest. 
Along the Andes of Quito, from Pasto to Guanca- 
bamba, it reaches close up to the eastern base of the 
mountains, and even ascends their lower slopes. In the 
moderately elevated country between the river Huallaga 
and Maranon, the forest extends only over the eastern 
portion, commencing in the neighbourhood of Moyo- 
bamba. Purther on, to the east of Cuzco and La Paz, it 
spreads high up on the slopes of the Bolivian Andes, and 
passing a little to the west of Santa Cruz de la Sierra, 
turns off to the north-east, crossing the Tapajoz and 
Xingu rivers somewhere about the middle of their course, 
and the Tocantins not far above its junction with the 
Araguaya, and then passes over to the river Parnaiba, 
which it follows to its mouth. 
The Island of Marajo, at the mouth of the Amazon, has 
its eastern half open plains, while in the western com- 
