If, when the Plantation has been thus neglected, a person is called in who does not fully understand what he is about, irreparable mischief will be done: he is almost sure to thin _too freely_. A proprietor of long neglected Plantations must, therefore, be well assured beforehand, that the person he employs will be guided in the course he takes by correct views, both practical and scientific, upon the whole subject; and when such is the case, the most suitable and appropriate plans will be adopted. Should any one demand of me before I close, some data on which he may judge whether or not a Plantation is in a condition requiring unusual attention, I offer the following: First: If, upon examination, it be found that the trees intended for timber have not an aspect and position superior to the others which are around them: Secondly: If, at any period after twenty years from the time of planting, it be found difficult to identify and point out the trees which are to be the final crop: Thirdly: When there are any decided indications of a want of health and vigour, there is proof sufficient that something more is required to be done than has yet been done. The grosser cases of Plantations which have never been entered for any purpose, for five, ten, fifteen, or twenty years together, need not be pointed at. Every one who sees them must perceive the necessity of their being relieved without loss of time. No plant, of which we have any knowledge, can exist without light and air, and in proportion to the extent to which they are excluded from Plantations, will be the injurious effect produced upon the health of the trees. In fact, it may be laid down as a universal rule, that _in proportion to the judgment and discrimination which are exercised in gradually admitting both light and air into Plantations, of almost every description_, will be their healthy progress. I conclude my remarks on this part of my subject by observing that, having admitted, as I most fully and readily do, that a _few_ instances may be met with in almost every county where the science of Arboriculture is tolerably well understood, and its principles carried out, I must still contend that cases enough may be found—First; of a want of preparation of the ground: Secondly; of an improper selection of plants, either as to kind or size: Thirdly; of an unsuitable admixture of them: Fourthly; of mistakes committed as to their distance from each other: Fifthly; when they are injured for want of early attention: Sixthly; when injury is done to them for want of, or from imprudent, or excessive, thinning, to fully justify me, or any one else, in bringing before the public the “_mismanagement_” of Plantations. CHAP. III. HEDGE-ROW TIMBER.