_August 19th._—To-night at ten o’clock we go on board the steamer, and before dawn shall be on our way up the river. This has been a delicious week of rest and refreshment to me. The quiet country life, with morning walks in the fresh, fragrant lanes and roads immediately about us, has been very soothing after four months of travel or of noisy hotel life. The other day as we were going into town we found in the wet grass by the roadside one of the most beautiful mushrooms I have ever seen. The stem was pure white, three or four inches in height, and about half an inch in diameter, surmounted by a club-shaped head, brown in color, with a blunt point, and from the base of this head was suspended an open white net of exquisitely delicate texture, falling to within about an inch of the ground; a fairy web that looked fit for Queen Mab herself.[48] The week, so peaceful for me, has been one, if not of rest, at least of intense interest for Mr. Agassiz. The very day of his arrival, by the kindness of our host, his working-rooms were so arranged as to make an admirable laboratory, and, from the hour he entered them, specimens have poured in upon him from all quarters. His own party make but a small part of the scientific corps who have worked for and with him here. In Pará alone he has already more than fifty new species of fresh-water fishes; enough to reveal unexpected and novel relations in the finny world, and to give the basis of an improved classification. He is far from attributing this great success wholly to his own efforts. Ready as he is to work, he could not accomplish half that he does, except for the active good-will of those about him. Among the most valuable of these contributions is a collection made by Mr. Pimenta Bueno, of the so-called fishes of the forest. When the waters overflow after the rainy season and fill the forest for a considerable distance on either side, these fish hover over the depressions and hollows, and as the waters subside are left in the pools and channels. They do not occur in the open river, but are always found in these forest retreats, and go by the name of the “Peixe do Mato.”