_June 14th._—Since our return from Tijuca we have been almost constantly in town, Mr. Agassiz being engaged, often from early morning till deep into the night, in taking care of the specimens which come in from every quarter, and making the final preparations for the parties which he intends sending into the interior. The most important of these, or rather the one for which it is most difficult to procure the necessary facilities, is bound for the upper course of the San Francisco. At this point one or more of their number will strike across the country to the Tocantins, and descend that river to the Amazons, while the others will follow the valley of the Piauhy to the coast. This is a long, difficult, but, as we are assured, not a dangerous journey for young and vigorous men. But wishing to anticipate every trouble that may befall them, Mr. Agassiz has made it his business to ascertain, as far as possible, the nature of the route, and to obtain letters to the most influential people for every step of the road. This has been no light task; in a country where there are no established means of internal communication, where mules, guides, camaradas, and even an armed escort may be necessary, and must be provided for in advance, the preparation for a journey through the interior requires a vast deal of forethought. Add to this the national habit of procrastination, the profound conviction of the Brazilian that to-morrow is better than to-day, and one may understand how it happens that, although it has been a primary object since our arrival to expedite the party to the Tocantins, their departure has been delayed till now. And yet it would be the height of ingratitude to give the impression that there has been any backwardness on the part of the Brazilians themselves, or of their government, to facilitate the objects of the expedition. On the contrary, they not only show a warm interest, but the utmost generosity, and readiness to give all the practical aid in their power. Several leading members of the Cabinet, the Senate, and the House of Representatives have found time now, when they have a war upon their hands, and when one ministry has been going out and another coming in, not only to prepare the necessary introductions for these parties from Rio to the Amazons, but also to write out the routes, giving the most important directions and information for the separate journeys.[34] Yet with the best will in the world the Brazilians know comparatively little of the interior of their own country. It is necessary to collect all that is known from a variety of sources, and then to combine it as well as may be, so as to form an organized plan. Even then a great deal must be left to be decided in accordance with circumstances which no one can foresee. No pains have been spared to anticipate all the probable difficulties, and to provide for them as far as it is humanly possible to do so; and we feel that