BRAZIL.—Mr. Herbert H. Smith has returned to Baltimore, U.S., after an absence of several years employed in scientific explorations in Brazil. Leaving the United States in January, 1874, for Pará, he ascended the Amazon to Santarem, where he was engaged for two years in collecting and studying the insect fauna of that region. Subsequently he extended his explorations to the north side of the Amazon and on the tributary rivers, as far as the base of the great northern table-land. A collection of insects made by him during this period amounted to 12,000 species, with 100,000 specimens, accompanied by copious notes on the habits, geographical distribution, &c. During 1876 and the early part of 1877 he was connected with the Brazilian Geological Commission in examining the geological structure of the country. He succeeded in making a section of the Devonian rocks of the Amazon region, and discovered a rich carboniferous bed on the north side of the Amazon, in the vicinity of Alenguer. The results of this labour are in the course of publication by Prof. Harrt, of the Geological Survey. Several months of his absence were spent in the southern part of Brazil, near Rio de Janeiro and Minas. Mr. Smith has been able to make some interesting inferences in regard to the geological distribution of Brazilian animals. Bates and Wallace have pointed out that the Amazon forms a limit to the migration of many animals. Mr. Smith is of the opinion that the flood plains of the valley, which average forty miles in width, constitute a far more effectual barrier than a body of water of the same breadth. Birds and insects of powerful flight pass this distance without difficulty, and are generally found on both sides; but the sluggish species, especially the wingless forms, like spiders, are generally confined to one side or the other. This is especially shown in those hymenopterous species in which the females are wingless, as the mutillarias, pezomactri, &c. Here the distinction between the northern and southern groups is very striking. The broad alluvial belt through which the Amazon flows constitutes a very distinct zoological province, in which many of the forms appear to have been derived from those of the high land. The contributions of Mr. Smith to geographical knowledge have not been inconsiderable. His maps of the physical geography of the Lower Amazon and of three important tributaries, the Curna, the Mæcurú, and the Jaurucú, are especially noteworthy. The last-mentioned has been entirely lost sight of by modern geographers, though referred to by earlier travellers. This enters the delta of the Xingú close to the Amazon, and is apparently navigable for steamers to a distance of 150 miles from its mouth. Mr. Smith returns to the United States for, the purpose of making arrangements for continuing his explorations for several years longer, so as to accumulate a sufficient body of facts to work out satisfactorily the entire problem of the derivation and the geographical distribution of the insects of Brazil.