Russel Wallace : Alfred Russell Wallace (sic)
"If any one is curious about our trip up the Tocantins, you may inform them that we ascended to about the 4th parallel of S. lat. near the Rio Tabocas, having reached Arroya, the last abode of civilized people, and passed a little beyond to view the rapids called Guaribas. We hired one of the heavy iron boats with two sails for the voyage, with a crew of four Indians and a black cook. We had the usual difficulties of travellers in this country in the desertion of our crew, which delayed us six or seven days in going up; the voyage took us three weeks to Guaribas and two weeks returning. We reached a point about twenty miles below Arroya, beyond which a large canoe cannot pass in the dry season, from the rapids, falls and whirlpools which here commence and obstruct the navigation of this magnificent river more or less to its source; here we were obliged to leave our vessel and continue in an open boat, in which we were exposed for two days, amply repaid however by the beauty of the scenery, the river (here a mile wide) being studded with rocky and sandy islets of all sizes, and richly clad with vegetation; the shores high and undulating, covered with a dense but picturesque forest; the waters dark and clear as crystal; and the excitement in shooting fearful rapids, &c. acted as a necessary stimulant under the heat of an equatorial sun, and thermometer 95° in the shade. Our collections were chiefly made lower down the river. During the five weeks of our journey we had no rain till the last two days. The weather here is as delightful as ever; the mornings invariably fine, and a shower in the afternoon every third or fourth day, which cools and refreshes everything delightfully. The heat is never oppressive; the nights always cool; there can certainly be no climate in the world superior to this, and few equal. Since sending our last collection, we have had further experience of the rarity of insects in this country. The Lepidoptera are numerous in species, but not in individuals; the Coleoptera are exceedingly scarce, and other orders are [[p. 75]] generally, like the Lepidoptera, sparing in individuals; we attribute it to the uninterrupted extent of monotonous forest over which animal life is sparingly but widely scattered. However this makes a difference in the commercial value of the subjects. The present collection is the fruits of two months' devoted and almost exclusive attention to insects. Shells and Orchids continue to be exceedingly scarce."