“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 {262} 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 functions; 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.” “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.” “That, as the four protecting properties, {263} already delineated, as belonging to trees in open situations, are essential and necessary to the vigorous development of their existence, so they may be set down as indispensable prerequisites for those intended for transplantation, which generally implies increased exposure; and that soil and climate being equal, such subjects will succeed the best as are endued in the greatest degree with those prerequisites or properties.”