[[p. 61]] Mr. Wallace said he went about a thousand miles up the Amazon and ascended the Rio Negro. During the four years he spent there, he acquired all the information he could respecting the country. The surface is covered with the largest unbroken forest in the world; it is the great physical feature of South America. At the mouth of the Amazon the forest extends only a few hundred miles into the interior, and then you get to the mountainous district of Brazil and Guiana, which is partly open country mixed with wood. Farther up the river an enormous plain opens out north and south, extending to the foot of the Andes, entirely covered with forest. The forest is of such [[p. 62]] extent that countries like England, France, Spain, and Germany might be thrown down in different parts of it, and they would be absolutely lost there--you might travel about for years and never hit upon them. It is an interesting problem to ascertain why it should cease so abruptly to the north and to the south. To the north you come at once to the open grassy plains on the Orinoco, and to the south you come to similar open plains on the Paranà. The river is also equally note-worthy from its enormous extent and the isolation of those nations that dwell in the interior. The people, the greater part of them, are utterly ignorant of any other country but their own except by vague report. All their ideas of geography are connected with this river; the position of other countries is conceived of as either on one side of the river or the other. Even comparatively educated people, Brazilians and Spaniards, who have been born and educated there, in questioning him about France and England, have asked on which side of the river they are situated. They imagine that the Amazon river flows all round the world, and that every country must be situated on one side or the other.