Mr. Wallace and Mr. Bates are well-known advocates of Mr. Darwin's theory of natural selection. The former gentleman was Mr. Bates's companion in travel for four years, and he has published a very interesting account of his voyage on his return to England. Whatever differences of opinion there may be with respect to {182} the celebrated work which Mr. Darwin gave to the world four or five years ago, unbiassed and thoughtful naturalists must recognize the force with which the author supports many of his arguments, and the fairness with which he encounters every difficulty. The competition displayed by organized beings is strikingly manifested in the Brazilian forests. So unmistakable is this fact, that Burmeister, a German traveller, was painfully impressed with the contemplation of the emulation and "spirit of restless selfishness" which the vegetation of a tropical forest displayed. "He thought the softness, earnestness, and repose of European woodland scenery were far more pleasing, and that these formed one of the causes of the superior moral character of European nations;" a curious question, which we leave to the consideration of moral philosophers. The emulation displayed by the plants and trees of the forests of Pará is thus spoken of by Mr. Bates: "In these tropical forests each plant and tree seems to be striving to outvie its fellow, struggling upward toward light and air--branch, and leaf, and stem--regardless of its neighbors. Parasitic plants are seen fastening with firm grip on others, making use of them with reckless indifference as instruments for their own advancement. Live and let live is clearly not the maxim taught in these wildernesses. There is one kind of parasitic tree very common near Pará which exhibits this feature in a very prominent manner. It is called the Sipó Matador, or the Murderer Liana. It belongs to the fig order, and has been described by Von Martins in the 'Atlas to Spix and Martius's Travels.' I observed many specimens. The base of its stem would be unable to bear the weight of the upper growth; it is obliged, therefore, to support itself on a tree of another species. In this it is not essentially different from other climbing trees and plants, but the way the matador sets about it is peculiar, and produces certainly a disagreeable impression. It springs up close to the tree on which it intends to fix itself, and the wood of its stem grows by spreading itself like a plastic mould over one side of the trunk of its supporter. It then puts forth from each side an arm-like branch, which grows rapidly, and looks as though a stream of sap were flowing and hardening as it went. This adheres closely to the trunk of the victim, and the two arms meet on the opposite side and blend together. These arms are put forth at somewhat regular intervals in mounting upward, and the victim when its strangler is full grown becomes tightly clasped by a number of