"This district," he says, "seemed to be an epitome of all that the humid portions of the Pará forest could produce. This endless diversity, the coolness of the air, the varied and strange forms of vegetation, the entire freedom from mosquitoes and other pests, and even the solemn gloom and silence, combined to make my rambles through it always pleasant as well as profitable. Such places are paradises to a naturalist, and if he be of a contemplative turn there is no situation more favorable for his indulging the tendency. There is something in a tropical forest akin to the ocean in its effects on the mind—man feels so completely his insignificance there and the vastness of nature. A naturalist cannot help reflecting on the vegetable forces manifested on so grand a scale around him."
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 inflexible rings. These rings gradually grow larger as the murderer flourishes, rearing its crown of foliage to the sky mingled with that of its neighbor, and in course of time they kill it by stopping the flow of its sap. The strange spectacle then remains of the selfish parasite clasping in its arms the lifeless and decaying body of its victim, which had been a help to its own growth. Its ends have been served—it has flowered and fruited, reproduced and disseminated its kind; and now when the dead trunk moulders away, its own end approaches; its support is gone, and itself also falls."
The strangling properties of some of the fig-tree family are indeed very remarkable, and may be witnessed not only in South America, but in India, Ceylon, and Australia. Frazer observed several kinds of Ficus, more than 150 feet high, embracing huge ironbark trees in the forests at Moreton Bay. The Ficus repens, according to Sir Emerson Tennent, is often to be seen clambering over rocks, like ivy, turning through heaps of stones, or ascending some tall tree to the height of thirty or forty feet, while the thickness of its own stem does not exceed a quarter of an inch. The small plants of this family, of which the Murdering Liana is one species, grow and reproduce their kind from seeds [{183}] deposited in the ground; but the huge representatives of the family, such as the banyan-tree, whose
"Bended twigs take root, and daughters grow
About the mother tree;"
and the Peepul, or sacred Bo-tree of the Buddhists (Ficus religiosa), originate from seeds carried by birds to upper portions of some palm or other tree. Fig-trees, as Sir E. Tennent has remarked, are "the Thugs of the vegetable world; for, though not necessarily epiphytic, it may be said that, in point of fact, no single plant comes to perfection or acquires even partial development without the destruction of some other on which to fix itself as its supporter." The mode of growth of these trees is well described by the excellent writer just mentioned, and we shall make use of his own language:
"The family generally make their first appearance as slender roots hanging from the crown or trunk of some other tree, generally a palm, among the moist bases of whose leaves the seed carried thither by some bird which had fed upon the fig begins to germinate. This root, branching as it descends, envelops the trunk of the supporting tree with a net-work of wood, and at length, penetrating the ground, attains the dimensions of a stem. But, unlike a stem, it throws out no buds or flowers; the true stem, with its branches, its foliage, and fruit, springs upward from the crown of the tree whence the root is seen descending; and from it issue the pendulous rootlets, which on reaching the earth fix themselves firmly, and form the marvellous growth for which the banyan is so celebrated. In the depth of this grove the original tree is incarcerated till, literally strangled by the folds and weight of its resistless companion, it dies and leaves the fig in undisturbed possession of its place." [Footnote 25]
[Footnote 25: "Ceylon," i., p. 95]
But not trees alone do these vegetable garrotters embrace in their fatal grasp, ancient monuments are also destroyed by these formidable assailants. Sir E. Tennent has given an engraving of a fig-tree on the ruins at Pollanarrua, in Ceylon, which had fixed itself on the walls—-a curious sight, indeed—"its roots streaming downward over the ruins as if they had once been fluid, following every sinuosity of the building and terraces till they reach the earth." An extremely interesting series of drawings is now to be seen in the Linnean Society's room at Burlington House, illustrating the mode of growth of another strangling or murdering tree, of New Zealand, belonging to an entirely different order from that to which the figs belong (Urticaceae), namely, to one of the Myrtaceae. The association of garrotting habits with those of the stinging nettle family is apt enough, we may be inclined to think; but it is rather disappointing to meet with these disagreeable peculiarities in the case of the myrtle group; but such is the fact: the Rata, or Metrosideros robusta—as we believe is the species—-climbs to the summits of mighty trees of the forest of Wangaroa, and kills them in its iron grasp. But, notwithstanding these unpleasant impressions which "the reckless energy of the vegetation might produce" in the traveller's mind, there is plenty in tropical nature to counteract them:
"There is the incomparable beauty and variety of the foliage, the vivid color, the richness and exuberance everywhere displayed, which make the richest woodland scenery in northern Europe a sterile desert in comparison. But it is especially the enjoyment of life manifested by individual existences which compensates for the destruction and pain caused by the inevitable competition. Although this competition is nowhere more active, and the dangers to which each individual is exposed nowhere more numerous, yet nowhere is this enjoyment more vividly displayed."