the tops. In open exposures, on the other hand, the reverse of this is the case. The characteristics of these are the following: Stems stout and short; Bark thick and coarse; Tops extensive and spreading; Branches often reaching to the ground; with Roots extensive like the Tops, and throwing themselves out on every side. What, then, are we to conclude, from these remarkable discrepancies between Trees of the same species, although in different situations, but that Nature, which orders nothing in vain, has bestowed these properties for wise purposes, and that they are the best calculated, respectively, to realize, in those Trees, as great a complement of life, as their respective circumstances will admit?

This conclusion naturally leads us to a closer attention to the progress of Wood, than is usually bestowed upon it. In infancy, that is, in the seed-bed, or nursery-ground, we find, that all plants of the same sort are alike, or nearly so. But, in a year, and, still more, in many years, when they go out to form plantations, they experience a great diversity of treatment, and are placed in soil of various qualities, and in various degrees of exposure. To these vicissitudes the plastic powers of plants, in process of time, accommodate themselves; so that, in point of form, character, and properties of every sort, they must essentially vary from one another, and acquire the properties, most suitable to such soils

and situations. It is for this reason, that, to establish any just analogy between the transplanting of Young Trees, and the transplanting of Old, is utterly impossible; because the circumstances in both cases being changed, the subjects under their influence change in consequence. *

In considering the characteristics of Trees above mentioned, we should always bear in mind, that every production of nature is an end to itself, and that every part of it is, at once, end and mean. Of Trees in open exposures we find, that their peculiar properties contribute, in a remarkable manner, to their health and prosperity. In the first place, their shortness and greater girth of Stem, in contradistinction to others in the interior of woods, are obviously intended to give, to the former, greater strength to resist the winds, and a shorter lever to act upon the roots. Secondly, their larger heads, with spreading Branches, in consequence of the free access of light, are formed as plainly for the nourishment, as well as the balancing of so large a Trunk, and also for furnishing a cover, to shield it from the elements. Thirdly, their superior thickness and induration of Bark is, in like manner, bestowed for the protection of the sap vessels, that lie immediately under it, and which, without such defence from cold, could not perform their func

Note VI.

tions. Fourthly, their greater number and variety of Roots are for the double purpose of nourishment and strength; nourishment to support a mass of such magnitude, and strength to contend with the fury of the blast. Such are the obvious purposes, for which these unvarying characteristics of Trees in open exposures are conferred upon them. Nor are they conferred equally and indiscriminately on all Trees so situated. They seem, by the economy of Nature, to be peculiar adaptations to the circumstances and wants of each individual, uniformly bestowed in the ratio of exposure, greater, where that is more conspicuous, and uniformly decreasing, as it becomes less.

On the other hand, in the interior of woods, a universal tendency, for the reasons already stated, is observable in Trees, to rise to the light, to attain greater altitude, to form far smaller Heads, and taller, slenderer, and more elegant Stems. Here is found a milder and more genial climate; in which, by means of the calm generated by shelter, vegetation is not checked by cold, and, at the same time, is undisturbed by the external impediment of wind; and nature has no need, as in the case of exposures, to generate provisions necessary to mitigate the effect of evaporation, as has been above observed, or to endue each individual Tree with distinct and appropriate means of

defence against the elements. In this situation, the branches, and, in like manner, the roots, are much less extensive and numerous, than in the former instance, and the bark of a thinner and finer quality; all plainly indicating, that the Trees so situated do not require the same external protection. It is like the genial warmth of the seedbed, or the nursery; but where the roots have freedom to expand without interruption, and the leaves to prepare the Sap, without being vexed by the winds. In fact, so extraordinary is the difference between Trees of the same species, placed in the one situation, and in the other, that there is no visible mark of resemblance between them, excepting the Leaves. We may, however, perceive, that, as soon as the Tops gain the summit of the wood, their Branches are shortened towards that quarter, and both Branches and Spray are more thickly thrown out, to supply a defence against the storm. Further, we find, that the outside rows, partaking, in some measure, of the situation of Trees in exposures, obtain, in a proportional degree, the provisions adapted to such a situation, and, by consequence, a corresponding conformation and external character. In the same manner, we may observe, that, if a Tree of some size, which, in consequence of exposure, has acquired all the properties already noticed, as adapted to that situation, be transferred to the interior

of the wood, it will, in a few years, lay aside those properties, and assume all the others which have been described, as peculiarly adapted to its new circumstances.* Thus, the Law of Nature seems to be, that Shelter and Exposure, that is, Heat and Cold, have the power alike of diminishing or encreasing, of bestowing or taking away, what may be called the Protecting Properties.

It has been noticed above, that all Trees, in open situations, uniformly attain the highest state of natural perfection, of which they are susceptible; consequently, it is by such Trees, that the best, the toughest, and the most durable timber is produced. Yet, it is interesting to observe the beneficence of Providence, in providing for the accommodation of man. Were it not for the way, in which the external conditions of Trees, in woods and close situations, are modified, from whence could we procure the long and powerful beam, the straight, clean, and lengthened deal, and nearly all the wood that is employed, whether in civil, or naval architecture?

On considering these different phenomena, and comparing them with other facts, respecting the growth of Wood, which daily present themselves to our observation, the following conclusions, as adapted to practice, seem irresistible, and are agreeable to the Law of Nature on this subject.

* NOTE VI.