Another and more massive Palm appears, where a moment ago there was nothing but smooth ground and empty air. It is the Sugar Palm (Saguerus saccharifer), remarkable in its appearance for the swathes of what looks to be sackcloth of hair, in which its stem is enveloped. Each of its great pinnate leaves forms with the dilated base of its midrib a broad sheath, which springs out of a loose fold of this coarse cloth that is wrapped around it. And not only the bases of the still flourishing leaves are swathed in this natural textile fabric, but the dead and dry leaf-bases of the former leaves, which may be traced all down the stem. But let us look at this strange cloth: what is it? It is composed of the exterior fibres of the leaf-bases themselves, which in process of growth have partially separated themselves, and from which the parenchyma and the lamina have decayed away. The appearance of a woven fabric is deceptive; there is no interlacing; but its semblance is produced by the fibres lying in layers one over the other, and by some of them having a direction at right angles to the others. Originally all the fibres were parallel and longitudinal, but as they have been, in the growth of the leaf, pulled out laterally, the main fibres, which are indefinitely divisible, have adhered to each other at various parts, and the result has been that innumerable constituent fibrillæ have been stretched across from fibre to fibre.
Every square inch, then, of this sackcloth tells of the lapse of time; these horse-hair-like fibres were once green and vascular, enclosing a soft pulp; in short, they were a part of a verdant leaf; the reduction of each congeries of veins to this condition was a work of time, and this has been effected by many leaf-bases in succession.
An examination of this gomuti, as it is called, does not indeed help us to identify the actual interval lapsed in the history of the plant; but we may arrive at this from other considerations. The great sheathing bases themselves remain in numbers attached to the upper portion of the stem, though the greater portion of the midrib with the pinnæ has decayed and fallen; and in the lower part, where even the bases have disappeared, still broad lateral scars are left, marking off the stipe into horizontal rings, which are not less conclusively certain evidences of the former existence of similar bases, and therefore, still earlier, of leaves.
The Sugar Palm developes and matures on an average six leaves every year.54 On counting the dry leaf-bases, and the scars, I find on this trunk, a hundred and twenty: besides which there are about a dozen expanded leaves, and two visible, which are not unfolded. A hundred and thirty-four leaves then have left proofs of their existence here; which divided by six, gives about twenty-two years as the age of this Palm. This is the age of this tree, however, since it began to form a stem; but several years of infancy must be added to the sum, during which its fronds sprang in succession from the surface of the soil.
Look at this Areca. By-and-by it will grow to the loftiest stature attained by any of its tribe, and its noble crown of leaves will wave on the summit of a slender pillar a hundred and fifty feet in height. But at present it has no stem at all; the widely arching leaves diverge from a central point which is below the surface of the soil. Here, then, are no dead leaf-bases; here are no old historical scars: – have we any evidence of past time here? Yes, surely. See this fully developed leaf. It is composed of a stout midrib, along the two opposite edges of which grow, like the beards of a feather, narrow sword-like leaflets, separated from each other by intervals of about two inches. But this pinnate condition, – which is so inseparable from the developed leaf of a great division of the Palm tribe, that our idea of a palm-leaf almost always is that of an enormous feather, – is by no means the original state. Observe this young leaf which is not yet thoroughly expanded; the leaflets are, indeed, separated everywhere, except that the tips of all are connected by a very narrow ribbon of the common green lamina, which runs from one to another. In the fully opened leaves, this has been torn apart and is not distinguishable.
But, let us carefully open this still younger leaf, which is protruding like a thin green rod, or rather like a closed fan, from the centre of the crown. We must handle it delicately, for it is very tender. Now you see it is not pinnate at all; the leaf is as entire as a Musa leaf, which, indeed, it much resembles, except that each half is folded transversely, and then these transverse folds are packed one on another longitudinally, fan-fashion. Each of the transverse folds answers to a future leaflet. It is the development of the midrib in length that tears asunder the divisions of the lamina, and converts them into separate, and by-and-by remote, pinnæ.
It is manifest then that every leaflet on the midrib of a pinnate-leaved Palm is a record of past time, as real as the leaf-bases on the trunk, inasmuch as, in each case, there is ocular proof that the conditions of existence are different from what they have been. And yet in this case, the evidences are fallacious, since the Areca before us has even now been created.
Here is an extraordinary plant. Though no thicker than your little finger, it will be found almost a quarter of a mile in length.55 This is a kind of Cane (Calamus); its slender jointed and polished stem is encased in the closely-sheathing and tubular bases of the leaves, which are spiny on their midribs, spiny on their pinnæ, and horridly spiny on the long and tough whip-lash in which the point of each leaf terminates. This lengthened cord is studded, at intervals of a few inches, with whorls of stout and acute prickles which are hooked backwards, and performs an important part in the economy of the plant. We see how it sprawls along the ground a few yards, then climbs up a tall tree, runs over the summit, descends on the opposite side to the ground, mounts over another tree, and thus pursues its wormlike course. Now as the pinnate leaves are put forth at every joint, the formidably armed flagellum affords a secure holdfast to the climbing stem, which otherwise would be liable to be blown prostrate by the first gust of wind; the recurved hooks, however, catch in the leaves and twigs of the trees, and effectually maintain the domination of the prickly intruder.
It is obvious that every inch sprawled over by this trailing stem supposes all the previous inches of its lengthening course; that every successive joint implies the existence of all the earlier joints; that every whorl of spines involves the development of every former whorl. Yet our reasoning is at fault; there has been as yet no succession; the development has been simultaneous, for it is the development, not of growth, but of creation.
Enough of Palms. Look at this Agave. Its thick, fleshy, glaucous leaves, with spinous margins and pointed ends, are arranged in many whorls on the summit of a stem, which is scarcely visible, as it barely rises above the soil. From the centre of the crown springs the stately flower-stalk, itself a tree of forty feet in stature, having a cluster of yellow blossoms at the extremities of its candelabra-like branches.
Have we here any clue to the past history of the plant? The tall flower-stalk, it is true, is of rapid growth, its whole stature having been attained within three or four weeks. But those massive leaves! Each of these lasts many years, and their development is as slow as that of the flower-stalk is rapid. Certainly we cannot assign to this individual, in the very vigour of its inflorescence, an antiquity less than half a century, and perhaps it may be considerably more.
You are altogether wrong; for it is but just called into existence.
We pass on, and pause before a noble example of one of the stateliest of plants, – the Traveller's Tree (Urania speciosa). It is a great Musaceous plant, resembling one of those fans which in the Southern States of America are made by ladies out of the broad tail-feathers of a turkey. Its leaves, of vast size, consist of a broad oblong lamina of the most brilliant green hue, divided equally by a midrib which descends in a smooth cylindrical petiole, much longer than the lamina (which is itself eight feet or more in length). Each leaf-stalk terminates below in a great demi-sheath, out of which springs another, in a zigzag or distichous fashion, the whole diverging, as they rise, in the same plane.
Below the alternately-sheathing leaves, of which there are but eight at present existing, there are the bases of others, now dead, which, when alive, evidently followed the same arrangement; and these give place yet lower to rings, each partly surrounding a massive conical stem.
I fear we have no criterion for determining the exact age of such a plant as this from actual observations on its rate of growth. From the fewness of its existing leaves they probably endure a considerable time; but at all events here are indubitable evidences of successive generations of leaves which are now past and gone; some of which are represented by withered rib-bases, while older ones have left but the scars which indicate the positions on the trunk where once they stood. Here are distinct testimonies to the lapse of a considerable period of time since the magnificent Urania, began its existence. Yet we should err egregiously by giving credence to them, since these developments are all prochronic.
"What a lovely butterfly!" Nay, it is a flower: though it dances in the air with an insect's fluttering flight, and seems to present in its broad wings of yellow and orange, and in its long and slender members, an insect's form and hues, it is but a flower fixed at the end of a lengthened stalk, which hangs from, a mass of leaves and bulbs, seated in the fork of this huge mahogany-tree.
We will neglect the flower, curious and beautiful as it is, and examine this crowded mass of roots and fleshy leaves and oval bulbs.
Tracing the slender lengthened footstalk to its origin, we see that it springs from the lower part of a flat, ovate, or nearly round, ridged, pseudo-bulb, of a purplish-green hue, of which there are many, much crowded together. The point of issue of the flower-stalk is concealed by an enveloping husky scale, which is the withered condition of a former leaf. From the base of another bulb a thick obtuse cone is pushing forth, which is the commencement of a new leaf-shoot; and here is one considerably advanced. In this latter there is nothing very remarkable; it is a thick, growing shoot, formed by fleshy leaves nearly doubled together, each sheathed by its predecessor. But soon this will cease to grow, and the point will dilate into an oval bulb, which will be a reservoir of nutriment for the future flower. In fact it will add another to the matted mass of bulbs which are already accumulated, crowned with two great thick, leathery, ovate, brown-spotted leaves, and marked with the scars of the leaves which are now growing, but which will then have sloughed away.
In this Oncidium, then, we have evidently a record of many bygone processes. Before the flower could open, the flower-stalk must have been developed; before this, the pseudo-bulb must have been formed; before this, there must have been a well-formed leaf-shoot, which must have been first a conical bud pushing forth from some anterior bulb; – or, if that shoot had been the first of the mass, then it must have looked back to a seed, which of course looked back to the capsule of a pre-existent flower, and so on.
Yet this is all fallacious; for the Butterfly-flower is but just created.
As beautiful, if less curious, is the crowded spike of purple blossom that adorns the tall stalk of this terrestrial Orchis. The flower-stalk springs from the midst of a few large spotted leaves, which terminate below in an irregular fleshy tuber of glutinous consistence. This tuber is shrivelled, and is in process of exhaustion and decay; but a horizontal stem has pushed out underground, which has at its extremity a second tuber, as yet immature, but plump and swelling. This growing tuber contains the elements of the leaves and flower-spike of next season: the shrivelling one was, last year at this period, in exactly the same condition as the swelling one is now; it too was pushed out horizontally from a preceding one which was then shrivelling, and so backward. These pre-existing stages can with certainty be announced by the vegetable physiologist; who yet would be deceived in this instance, because the plant has been but just created.
This elegant Gladiolus that displays its tall spike of crimson blossoms from the midst of its flattened folded leaves, affords us a similar example of retrospective energy. If I dig away the light soil from around its base, I discover two globose corms, fleshy swellings of the stem, accumulations of nutriment obtained during the vegetative activity of the plant, and destined to support it during the season of inaction, and therefore stored up for that purpose.
The uppermost of these globose corms is that of the present season; it is as yet small and immature, being in process of formation by the assimilation, consolidation, and deposition of new matter by the action of the leaves. This is sheathed in the tubular bases of the leaves, which expand above; and it is seated on a larger, riper, and more spherical corm, which is wrapped in a brown fibrous skin. This is the matter which was deposited in the course of last spring and summer, and the brown skin is the remains of the leaves of last year. This corm has remained inactive, since the decay of last year's leaves, until this winter, when the root fibres, which we see descending from the lower surface, began to form, and an upward prolongation of the stem followed, which, as it grew, swelled into the upper corm.
In the centre of the under surface of the corm of last season, in a depression surrounded by the white root-fibres, there are some almost decayed remains of a deep brown hue. These are the last vestiges of the preceding year's corm, and they exhibit the condition in which the large corm will be next spring, when the small half-formed one will be in the state and position of this larger one, and will in like manner be surmounted by its rising successor.
Thus there are in this plant ocular proofs of two years' history before the present; yet these proofs are invalidated by the fact of its creation this day.
Behold now that singular plant, the Grass-tree (Kingia australis), displaying what seems an immense tuft of wiry grass elevated on the summit of a trunk which is formed of the united bases of myriads of decayed leaves, the representatives of many generations of these organs. The silvery leaves which constitute the existing crown, and the numerous spikes of blossom which stand up in a circle diverging from the midst of them, give to this plant a most striking effect. That, however, is not our present concern, but the evidences which we may be able to gather from it of a previous history. For some distance below the living leaves, the trunk is connected by the withered, hanging, but still persistent leaves of several successive developments, a ragged drapery, of which we might certainly say —
" – when unadorn'd, adorn'd the most."
The lower portion of the stem is, however, destitute of the decayed leaves themselves, the lozenge-formed bases of them alone remaining, still separable, indeed, but sufficiently compact to make in the aggregate a sub-cylindrical column of loose texture, which may in familiar parlance be termed a trunk. This portion is marked by alternate enlargements and constrictions of the outline, which appear to indicate seasonal growths.
The specimen before us is about twenty feet in height, exclusive of the crown; supposing these swellings to mark a year's growth, and to be continued in the same proportion on that part of the trunk which is masked by the decayed leaves as on the exposed part, we should conclude this tree to be about thirty-five years old; for there are about thirty-four such swellings, each of which contains about four hundred of the lozenge-shaped bases of the fallen leaves.56
Remember, however, that we are looking at the Grass-tree, not as it now appears on the sandy plains of Western Australia, in the nineteenth century, but as it came out of the hands of its Almighty Creator at some precise but unknown period of past time.
This White Lily, crowned with its cluster of nodding flowers, magnificently beautiful, each a fair emblem of the spotless purity of a noble virgin – if we remove the soil from its base, we shall find that the stem springs out of a fleshy bulb. This is covered with thick yellow scales, by taking away each of which in turn, we see that the bulb is made up of such, surrounding the central mass which has pushed upward, in the form of the stalk, with its leaves and flowers.
Now the whole of this beautiful array which we see was formed last summer, when, if we had divided the bulb longitudinally, we should have seen every leaf, every tiny blossom, folded together, and most snugly packed within the encircling scales, which are, indeed, undeveloped leaves; while from the base of the bulb so formed we should have seen pushed up on the outside of it, but yet within the common envelope of the exterior scales, the flower-stem of last season. There could not possibly have been this raceme of virgin blossom, if it had not been formed during the preceding season within the bulb; so that its existence is a record of a year's growth at least.
Yet this is the first hour of the lovely Lily's life; an hour ago it was not.
The face of the rugged cliff that rises perpendicularly above us was, a few moments ago, quite naked and bare, or diversified only by a few stunted prickly shrubs that sprang from its crevices. Now, by the mighty fiat of God, it is in an instant festooned from top to bottom with a most graceful drapery of round pale-green leaves, and slender stems no thicker than whipcord, and multitudes of spiral tendrils that climb, and hook, and catch, and entwine among the thorny bushes, and around the angles and prominences of the rock. We trace this curtain of verdure downwards, and find that it resolves itself into some half a dozen of wiry-stems, that issue from different points of the surface of what seems a boulder of brown stone, or a block of rough-hewn timber, at the foot of the cliff.
This angular block is, however, worthy of closer examination. It is of no definite form, huge and uncouth, lying as if cast accidentally on the ground. Its whole surface is divided into a multitude of polyhedral pieces, that look as if they had been cut into these forms by human art. Each division has a small angular face, and its sides display close parallel lines, all following the directions and angles of the outer face, but each line enclosing a slightly wider area than the one above it. These woody plates closely resemble in their angular forms and their concentric lines the plates of a Tortoise's shell, and hence our botanical friend, to whom we will appeal for an opinion as to the age of the block, will call the generic name Testudinaria.
"Well, I cannot give you any very precise judgment on the matter. The block itself is the tuber of a sort of yam, which grows above ground instead of below. It is a woody mass of great age. The angular plates are the bark, and they are so divided in consequence of the gradual growth of the tuber, tearing open its periphery to obtain more room. The concentric lines on the edges of the plates will not give us any adequate idea of the age of the mass, for though they indicate seasonal growths, the earlier layers have been worn away in the lapse of ages, and there are many layers of bark that have not yet been burst by the expansive force of the growing wood. It is known that these blocks are of very slow growth; in tropical regions they last, with scarcely perceptible increase, from generation to generation. From such vague data as we possess, I might loosely conjecture this tuber to be a thousand years old."
We thank our scientific friend, and think it a very satisfactory report on an organism, which we saw called into existence five minutes ago, before our eyes.
Come away; for I wish you to look at this Encephalalartos. A horrid plant it is, a sort of caricature of the elegant Palms, somewhat as if a founder had essayed a cocoa-nut tree in cast iron. Out of the thick, rough, stiff stem spring a dozen of arching fronds, beset with sharp, sword-shaped leaflets, but having the rigidity of horn, of a greyish hue, all harsh and repulsive to excess. In the midst of this rigid coronal sits the fruit, like an immense pine-cone.
The swelling column that constitutes the stem is but a mass of pith, surrounded by a thin case of wood, and enclosed by the remains of former leaves. The whole surface is covered with the lozenge-shaped scars of these, in vast number. Thousands of these there must be in this trunk of eight feet high, and a foot thick. The leaves of the existing crown are few and very durable, so that it would be no unreasonable conjecture to suppose that this great Cycadaceous plant is seven or eight centuries old.
Nay, for this also has been created even now!
What shall we say to this singular phenomenon? Observe yonder gigantic Fig (Ficus Australis) growing out of the face of that vast rocky precipice. It is not so much to the massive grandeur of the trunk, nor to the widespread head of dense foliage, that I call your attention, as to the broad expanse of roots, from the thickness of your body to that of your little finger, which have crossed and interlaced and separated and re-united, in all imaginable ways, until the whole forms a great flat network of wood, investing the surface of the rock, and following all its projections and angles with singular faithfulness, for a space of many square yards.
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.
TWIG OF TULIP-TREE.
Now it is manifest that the uppermost of the three leaves, together with the developing terminal bud, was at one time enclosed in the pair of bracts immediately below its base; that, before that, the middle leaf, with all above it, was similarly incarcerated in its own proper tracts; and, at a period anterior to that, the lowest leaf also. Each pair of bracts is therefore a record of a past period; and together they testify to a succession of past periods.
And yet their combined testimony is utterly worthless, because the noble tree was created in its magnificence this very day.
The beautiful twiner (Bignonia), which has cast its ample festoons over the topmost branches of yonder towering Mora-tree, almost concealing the natural foliage with its own elegantly pinnate leaves, and adorning it with its gorgeous trumpet-shaped flowers, is distinguished by a curious property, indicative of the years that have passed over it. In its adult maturity, as we now see it – the glory of this tropical forest – we should find, if we cut across the main stem, that its wood is divided into lobes arranged in a radiate or star-like fashion, like the divisions seen on dividing an orange transversely; and these lobes are thirty-two in number.
But this condition has not existed through the life of the plant. The wood has always been lobed, but the number of the divisions has varied, and that in geometrical ratio. Before the present stage, the constituent lobes were sixteen, which became thirty-two by the subdivision of each. In an earlier stage there were eight lobes, and, earlier still, four, which was the commencing number; the duplication having proceeded in each case by the fission of each of the existing lobes into two.57
Now though this phenomenon will afford us, on the data we at present possess, no insight into the age of the plant, considered as an actual chronological period, an examination of a transverse section would always determine which stage is then present, and, by consequence, how many previous stages have been passed through. And thus we obtain a distinct clue to the former history of the organism, though we cannot mark it off into months and years.
Yet the fact of creation stultifies all the conclusions that we might form from such premises; since it does, ipso facto, contradict every such thing as a previous history.
On this Anona there is an intruder more strictly parasitical; it is a Loranthus, with long, club-shaped, richly-coloured blossoms. The branches of the supporting tree – a nurse who feeds her foster-child on her own vital juices – are over-spread for a large space with the shoots; which, springing each from its own disk, appear like so many distinct individuals, but are really all parts of a single plant, springing from a single seed. (For this curious fact we are indebted to the observations of Mr. Griffith, who has investigated the singular history of these parasites.)
The ripe seeds firmly adhere to the substance on which they are applied, by means of their viscid envelope, which soon hardens into a transparent glue. In the course of two or three days, the radicle curves towards its support, and, as soon as it reaches it, becomes dilated and flattened. An union is gradually formed between the woody system of the parasite and that of the stock, after which the former lives exclusively on the latter, the fibres of the sucker-like root of the parasite expanding on the wood of the support in the form of a paté d'oie. Up to that time the parasite had been nourished by its own albumen, which is now exhausted. As soon as the young parasite has acquired the height of one or two inches, when an additional supply of nourishment is required, a lateral shoot is sent out, which is, especially towards the point, of a green colour. This at one, or two, and subsequently at various points, adheres to the support by means of sucker-like productions, which are precisely similar in structure and mode of attachment to the original seminal one. The fibres of the parasite never penetrate beyond their original attachment; in the adult the sucker-bearing shoots frequently run to a considerable distance, many plants being literally covered with parasites, all of which have originated from one and the same seed.58