Among the frequent visitors at the laboratory, and one to whom Mr. Agassiz was indebted for most efficient aid in making his collection of fishes from the harbor of Rio, was our friend Dr. Pacheco de Silva, who never lost an opportunity of paying us all sorts of friendly attentions. He added quite a number of luxuries to the working-room described above. Another friend who was often at the laboratory was Dr. Nägeli. Notwithstanding his large practice, he found time to assist Mr. Agassiz not only with collections but with drawings of various specimens. Being himself an able naturalist, his co-operation was very valuable. The collections were indeed enriched by contributions from so many sources that it would be impossible to enumerate them all here. In the more technical reports of the expedition all such gifts are recorded, with the names of those persons from whom the specimens were received. Footnote 20: The palm is the beautiful _Oreodoxa oleracea_. Footnote 21: Leuzinger’s admirable photographs of the scenery about the Corcovado, as well as from Petropolis, the Organ Mountains, and the neighborhood of Rio generally, may now be had in the print-shops of Boston and New York. I am the more desirous to make this fact known as I am indebted to Mr. Leuzinger for very generous assistance in the illustration of scientific objects.—L. A. Footnote 22: A commemorative tablet, set in the rocks on the dividing line between the provinces of Rio de Janeiro and Minas Geräes, recording the speech of the Emperor on the occasion of the opening of the road, testifies the appreciation in which this undertaking was held by the government of Brazil. Footnote 23: Since this was written the Emperor, at a large pecuniary sacrifice, has liberated all the slaves belonging to the property of the crown, and a general scheme of emancipation has been announced by the Brazilian government, the wisdom, foresight, and benevolence of which can hardly be too highly praised. If this be adopted, slavery in Brazil will disappear within the century by a gradual process, involving no violent convulsion, and perilling neither the safety of the slave nor the welfare of his master. Footnote 24: To the Baron de Mauá, a leader in the great improvements now going on in Brazil, the citizens of Rio de Janeiro owe their present convenient road to Petropolis, their favorite summer residence. Footnote 25: A species of Melastoma, with very large, conspicuous flowers.—L. A. Footnote 26: This is not, however, native to Brazil. Footnote 27: