The Gran Chaco, an immense region in the interior of the continent, said to be 2,500,000 square miles in extent, is, without doubt, the darkest part of "The Darkest Land." From time immemorial this has been given up to the Indians; or, rather, they have proved so warlike that the white man has not dared to enter the vast plain. The Chaco contains a population of perhaps 3,000,000 of aborigines. These are divided into many tribes, and speak numerous languages. From the military outposts of Argentina at the south, to the Fort of Olimpo, 450 miles north, the country is left entirely to the savage. The former are built to keep back the Tobas from venturing south, and the latter is a Paraguayan fort on the Brazilian frontier. Here about one hundred soldiers are quartered and some fifty women banished, for the Paraguayan Government sends its female convicts there. [Footnote: The women are not provided with even the barest necessities of life. Here they are landed and, perforce, fasten themselves like leeches on the licentious soldiery. I speak from personal knowledge, for I have visited the "hell" of Paraguay.] Between these forts and Bolivia, on the west, I have been privileged to visit eight different tribes of Indians, all of them alike degraded and sunken in the extreme; savage and wild as man, though originally made in the image of God, can be. The Chaco is a great unknown land. The north, described by Mr. Minchin, Bolivian Government Explorer, as "a barren zone--an almost uninterrupted extent of low, thorny scrub, with great scarcity of water," and the centre and south, as I have seen in exploring journeys, great plains covered with millions of palm trees, through which the astonished traveller can ride for weeks without seeing any limit. In the dry season the land is baked by the intense heat of the tropical sun, and cracked into deep fissures. In the rainy season it is an endless marsh--a veritable dead man's land. During a 200-mile ride, 180 lay through water with the sun almost vertical. All this country in past ages must have been the bed of a great salt sea. As I have said, the Chaco is peculiarly Indian territory, into which the white man steps at his peril. I accepted a commission, however, to examine and report on certain parts of it, so I left the civilized haunts of men and set foot on the forbidden ground.