Would you not say, admitting that the Figs are rapid growers, that many years must have elapsed since the minute seed was dropped in yonder crevice, by some vagrant parrot that wiped his beak after breakfast on the point of rock? Would you not say that many years must have passed from the time when the tiny shoot peeped from the rocky chink, to the present moment, when the leafy honours of the crown above and the woody wall of the roots below combine to repay the protection which the plant in infancy received from its stony foster mother?
Of course you would; and most truly too, did you not know that the Fig-tree is now rejoicing in the first hour of its new-created being.
So with its noble congener here, the many-trunked Banyan (Ficus Indica). Although not an old tree, its canopy of broad downy leaves is already supported by so many secondary trunks, that it is not easy to say which of the larger stems is the mother trunk, and which the hopeful daughters. Every one of these stems, some just protruding from the horizontal limbs, others hanging midway between the leafy roof and the earth, some just inserting their slender spongy tips into the soil, others thick and pillar-like—is an evidence of progressive development, and therefore of lapsed time; only for the qualifying fact, that the development in this case is prochronic.
Here is the great Euphorbia grandidens of Africa. Its stout trunk is marked with a number of holes, some four or five inches apart, arranged in perpendicular rows. In some cases they are rather depressions or pittings than holes, and look like what would result from borings made with an auger in pitch in warm weather, the margins of which had nearly closed, subsequently. What is the explanation of these marks? They are all records of time. From each of these spots once grew one of those angular prickly branches, that look like our commonest sorts of Cactus, and which are now confined to the summit of the trunk, arching out from it, somewhat like the branches of a candlestick.
It is the habit of this plant, when the stem has acquired a certain thickness, that the branches should, after a time, decay and drop off at the point of their union with the trunk, or rather a little below the surface, so as to leave the shallow holes or pits which we see. After their decadence, the growing bark gradually swells around the scars, and has a tendency to obliterate them. This may account for the non-appearance of them on the lower parts of the stem.
Here, then, are demonstrations of several successive stages of development. First, the stem must have been in existence before any lateral branches could have sprung from it. Secondly, the branch shot out. Thirdly, it put forth its spines and leaves. Fourthly, it died and sloughed away. Fifthly, the growing bark encroached on, and finally obliterated the cicatrice.
In this individual, all these stages are illusory, or rather they are prochronic.
See this noble Tulip-tree (Liriodendron tulipiferum), a giant of this primeval forest; its towering trunk is crowned with a head of large massy foliage, of a rich deep verdure, among which shine numbers of great golden tulip-like blossoms, as fragrant as beautiful.
It is, however, the leaves that grow on the terminal twigs that I wish you specially to notice. These, which, as you see, are large, and of a remarkably elegant form, are fixed at the end of long petioles, which are set alternately on the twig. Notice, now, the manner of their development; the young unexpanded leaves grow within two large leaf-like bracts, forming an oval sac, which, as the young leaf increases, swell, and at length burst, and are left on each side of the base of the leaf-stalk. There is a succession of these. On this growing twig, for instance, I find three leaves already expanded (a a a in the accompanying figure), and as many pairs of these bracts (b b b) at their bases; the twig is terminated by a pair (c) convex outwardly, and whose edges are in contact with each other; if, now, I cut off one of these (as represented at d), I expose the next leaf (e) folded together, and bent downward, in its pretty manner of vernation; beside it is another pair of bracts (f), whose edges are not only in contact, but mutually adherent, and that with considerable force. On tearing these apart, I discover another smaller leaf, and another smaller pair of adhering bracts, which again contain a similar set, only yet more minute, and so on in succession, till I can no longer trace them.