I have never forgotten the impression which I received of the luxuriant power of vegetation in the tropical world, when on entering a Cacao plantation (Caca hual), in the Valles de Aragua, after a damp night, I saw for the first time large blossoms springing from a root of the Theobroma deeply imbedded in black earth. It was one of the most instantaneous manifestations of the activity of the vegetative organic forces. Northern nations speak of the “awakening of Nature at the first breath of the mild air of spring.” Such an expression is singularly contrasted with the imagination of the Stagirite, who recognised in plants forms which “lie buried in a tranquil slumber that knows no waking, free from the desires which impel to spontaneous motion.” (Aristot. de generat. Animal. V. i. p. 778, and de somno et vigil. cap. 1, p. 455, Bekker.)
[36] p. 30.—“Draw over their heads.”
The flowers of our Aristolochia cordata, to which I have already referred in Note [25]. The largest flowers in the world, apart from Compositæ (in the Mexican Helianthus annuus), belong to Rafflesia arnoldi, Aristolochia, Datura, Barringtonia, Gustavia, Carolinea, Lecythis, Nymphæa, Nelumbium, Victoria regina, Magnolia, Cactus, and to Orchideous and Liliaceous plants.
[37] p. 31—“To behold all the shining worlds which stud the heavenly vault from pole to pole.”
The finest portion of the southern celestial hemisphere, where shine the constellations of the Centaur, the Ship, and the southern Cross, and where the soft lustre of the Magellanic clouds is seen, remains for ever concealed from the view of the inhabitants of Europe. It is only beneath the equinoctial line that Man enjoys the peculiar privilege of beholding at once all the stars both of the Southern and the Northern heavens. Some of our northern constellations seen from thence appear from their low altitude of a surprising and almost awful magnitude: for example, Ursus major and minor. As the inhabitant of the tropics sees all the stars of the firmament, so also, in regions where plains alternate with deep valleys and lofty mountains, Nature surrounds him with representatives of all the forms of plants.
POSTSCRIPT
ON THE
PHYSIOGNOMIC CLASSIFICATION OF PLANTS.
In the preceding sketch of a “Physiognomy of Plants,” I have had principally in view three nearly allied subjects:—the absolute diversity of forms; their numerical proportion, i. e. their local predominance in the total number of species in phænogamous floras; and their geographic and climatic distribution. If we desire to rise to general views respecting organic forms, the physiognomy of plants, the study of their numerical proportions (or the arithmetic of botany),—and their geography (or the study of their zones of distribution),—cannot, as it appears to me, be separated from each other. In the study of the physiognomy of plants, we ought not to dwell exclusively on the striking contrasts presented by the larger organic forms separately considered, but we should also seek to discern the laws which determine the physiognomy of Nature generally, or the picturesque character of vegetation over the entire surface of the globe, and the impression produced on the mind of the beholder by the grouping of contrasted forms in different zones of latitude and of elevation. It is from this point of view, and with this concentration or combination of objects, that we become aware, for the first time, of the close and intimate connection between the subjects which have been treated of in the foregoing pages. We are here conducted into a field which has been as yet but little cultivated. I have ventured to follow the method first employed with such brilliant results in the Zoological works of Aristotle, and which is especially suited to lay the foundation of scientific confidence,—a method which, whilst it continually aims at generality of conception, seeks, at the same time, to penetrate the specialities of phenomena by the consideration of particular instances.
The enumeration of forms according to physiognomic diversity is, from the nature of the case, not susceptible of any strict classification. Here, as everywhere else, in the consideration of external conformation, there are certain leading forms which present the most striking contrasts: such are the groups of arborescent grasses, plants of the aloë form, the different species of cactus, palms, needle-trees, Mimosaceæ, and Musaceæ. Even a few scattered individuals of these groups are sufficient to determine the character of a district, and to produce on a non-scientific but sensitive beholder a permanent impression. Other forms, though perhaps much more numerous and preponderating in mass, may not be calculated either by the outline and arrangement of the foliage, or by the relation of the stem to the branches,—by luxuriant vigour of vegetation,—by cheerful grace,—or, on the other hand, by cheerless contraction of the appendicular organs, to produce any such characteristic impressions.
As, therefore, a “physiognomic classification,” or a division into groups from external aspect or “facies,” does not admit of being applied to the whole vegetable kingdom, so also, in such a classification, the grounds on which the division is made are quite different from those on which our systems of natural families and of plants (including the whole of the vegetable kingdom) have been so happily established. Physiognomic classification grounds her divisions and the choice of her types on whatever possesses “mass,”—such as shape, position and arrangement of leaves, their size, and the character and surfaces (shining or dull) of the parenchyma,—therefore, on all that are called more especially the “organs of vegetation,” i. e. those on which the preservation,—the nourishment and development,—of the individual depend; while systematic Botany, on the other hand, grounds the arrangement of natural families on the consideration of the organs of propagation,—those on which the continuation or preservation of the species depends. (Kunth, Lehrbuch der Botanik, 1847, Th. i. S. 511; Schleiden, die Pflanze und ihr Leben, 1848, S. 100). It was already taught in the school of Aristotle (Probl. 20, 7), that the production of seed is the ultimate object of the existence and life of the plant. Since Caspar Fried. Wolf (Theoria Generationis, § 5-9), and since our great (German) Poet, the process of development in the organs of fructification has become the morphological foundation of all systematic botany.
That study, and the study of the physiognomy of plants, I here repeat, proceed from two different points of view: the first from agreement in the inflorescence or in the delicate organs of reproduction; the second from the form of the parts which constitute the axes (i. e. the stems and branches), and the shape of the leaves, dependent principally on the distribution of the vascular fascicles. As, then, the axes and appendicular organs predominate by their volume and mass, they determine and strengthen the impression which we receive; they individualise the physiognomic character of the vegetable form and that of the landscape, or of the region in which any of the more strongly-marked and distinguished types severally occur. The law is here given by agreement and affinity in the marks taken from the vegetative, i. e. the nutritive organs. In all European colonies, the inhabitants have taken occasion, from resemblances of physiognomy (of “habitus,” “facies”), to bestow the names of European forms upon tropical plants or trees bearing very different flowers and fruits from those from which the names were originally taken. Everywhere, in both hemispheres, northern settlers have thought they found Alders, Poplars, Apple- and Olive-trees. They have been misled in most cases by the form of the leaves and the direction of the branches. The illusion has been favoured by the cherished remembrance of the trees and plants of home, and thus European names have been handed down from generation to generation; and in the slave colonies there have been added to them denominations derived from Negro languages.