According to the received doctrines in Botany, in the case of exogens, a wood or leaf bud in development, forms an axis or branch with its appropriate leaves, arranged in an order peculiar to each genus; each leaf, in its foot stalk, being furnished with an inner and an outer set of ducts and vessels, which vessels, in the course of a growing season descend by extension to the roots; the inner set upon the smooth, cylindrical surface of the alburnum; the outer, (if Lindley's notions of the proper office of cambium be true,) upon the inner surface of the bark; the annual deposit of wood and bark lying between these inner and outer ducts and vessels. In time, during the season's growth, anastomosis takes place in the axilla of every such leaf; a new wood bud is formed and installed upon the apex of the bundle of vessels, woody fibre and bark, which, originating in the foot stalk as before stated, has already descended by extension to the roots.

In this way, every wood bud is in a state of direct communication with the roots, rendy by vitality and capillarity, to pump up supplies of food for the formation of still other leaves and branches - destined in their turn, still farther to increase the vigor and size of the trunk and roots. A fruit bud is a metamorphosis of one of these wood buds; " it is a wood bud excited into growth; but which, in growing, elongates neither upward nor downward." It is obvious then, that being seated in connection with vessels extending to their roots, the fruit bud pumps for itself food from the general circulation, but not extending downwards in growth, it has no chance by which to send succor and strength to the stem and roots. The fruit bud is, therefore, a sort of parasitical plant, living at the expense of the wood system, and as it is generally expressed, in a state of " antagonism with it." To the practical cultivator, it is a matter of secondary interest whether this metamorphosis result from some innate power peculiar to the life of plants, as the learned Dr. Lindlbt supposes - or is brought about by some outward circean agency everywhere present, and ready to act, under proper conditions, as the luminous ray of the compound sunbeam, which is the theory of a certain French philosopher.

But the propositions themselves, being admitted to be true, there are certain hints which may be drawn from them as corollaries, and which will prove instructive in a high de gree, to the farmer, pomologist and gardener. Two of them I propose to consider briefly in the present article.

1st. That in exogens, which include most fruit trees, the normal place of the fruit bud is within the circuit of circulation, and that generally, its appearance at the extremities of leading branches, is an evidence of over-fruitfulness and disability, if not disease.

2d. That as from organization, the fruit spur system is supported out of the general circulation, upon the principle of parasites, and maintains what is termed " the balance of power," by absorbing just so much of the general circulation as prevents over-luxuriant growth in the wood system - no more and no less: too great a diminution of the wood spurs has a tendency to over-stimulate the wood growth.

If we attempt to look around for evidences of the injury which trees and plants sustain, where fruit buds are allowed to take possession of the extremities of the main wood branches, and to cover the whole outer surface, we can hardly go astray, whether in the orchard or garden, especially when the plantations have been of long standing. Do we see the bearing branches of the gooseberry or currant bristling with thick and pointed clusters of fruit buds to their very ends? If so, it may be set down as a truth, that such branches are destined to perish at a day not remote. If again, we examine the pear and the apple, and find the whole exterior surface of the trees covered with fruit buds and fruit spurs, such a staite of things is evidence of present debility, or a most pregnant sign of its speedy approach; indeed whole families of fruit trees (heavy bearers generally,) are sometimes seen to blight in this way - the wood system being stifled and supplanted by these parasitic spurs, and only re-appearing amid the dying throes of the tree, under the shape of " water-sprouts," in the body and large branches of the tree, where they break out in clusters, not unlike those present in the peach tree when affected with " yellows".

If one were skeptical of the doctrine of botanists, that fruit buds add nothing to the wood system, it would be quite easy to remove such doubting by a little personal examination of trees upon which the fruit bud system is developed in great excess. Numberless examples might be found of branches not larger than rye-straws, terminated by fruit buds, showing unerringly an age of three or more years, while such branches themselves show no increment of wood over and above the annual ring of the first season's growth; in fact, in such cases, the order of nature seems inverted, and instead of that taper growth from the trunk upward and outward, which marks and makes beautiful a tree in health, those fruit spurs go on enlarging and multiplying, until the thickening and bloated masses of debility darken and almost obstruct the view.

In illustration of the second point proposed, I shall draw largely upon individual experience, and hope that I may state,without being thought presumptuous, that my fruit crops, for some years, have presented a uniformity of appearance which has led some persons, and especially the less experienced, to suppose the result asoribable to the possession on my part, of some secret in the art of cultivation. I hardly need say that such is not the feet, and that I have never based a hope upon any other foundation than good culture, aided by a practice in pruning and training, conducted in accordance with the natural habit of each genus. But in efforts to acquire a knowledge of these natural habits, (which knowledge constitutes in part the science of pomology,) I have, altar having endeavored to avail myself of all the light shed upon this subject by others, sometimes perpetrated egregious errors, and perhaps I never committed an error more egregious in character, or more expensive in its consequences, than one in relation to the nature of this very fruit bud system, or spermoganous force.

I term this error expensive, because in adopting a practice of pruning the peach and pear in conformity thereto, I lost a large part of the general crop in several bearing years, for the want of bloom.

Anterior to about the period 1847,1 was, when growing fine fruits, in the habit of thinning the crop by removing a large portion of the fruit spurs with the fruit attached, leaving only those bearing the specimens intended to be ripened, and with the peach particularly, by way of monsterizing individual fruits, I reduced the whole count to a very small number upon certain young trees, nor was this practice abandoned till I saw branches of bearing trees, thus treated, running up into a nursery growth, the "tout ensemble" of which branches resembled more a thicket of young trees than a well proportioned individual tree. Indeed I have been more than once mortified to see fruits treated thus, and from which so much was expected, come to a perfect stand still; the whole crop of certain individual trees, ultimately writhing, growing yellow and dropping without maturity, whilst the buds of the current season would swell and burst into active wood growth.

These fruit spurs being in the nature of parasites, possessing and enjoying supplies of food obtained at the expense or the wood system, exist in a state of antagonism therewith, and holding forcible possession of the power to feed upon the general circulation, they must exist in such numbers, collectively, as will enable them, as a system, to keep in check the wood-growing force, the constant tendency of which is to a monopoly of the whole circulation, and to a growth of over luxuriance. Although it is a maxim generally received as a truth, that in sharing out any given stock of supplies, the fewer the distributees the greater the distributive share. The functions performed by the fruit-buds col-lectively as a system in this case, qualified the applicability of this maxim. When I thinned the crop by removing the spurs up to a given point, the operation might be salutary; further diminution disturbed the balance of power, and diminution carried to extremes stimulated the wood growth to a luxuriance which for a time suspended the development of fruit buds of a healthy character.

Although my remarks concerning the nature of these two forces have been confined to exogens, it by no means follows that a knowledge of them in other families of plants is either unattainable or useless. Such knowledge is not unattainable, since among cereals any experienced farmer will in early spring, long before the wheat plant has shot into culm, and as for off as the eye can discern colors, pronounce upon the promise of any wheatfield for a crop abounding more or less in straw or grain, as the dark green of luxuriance or the more subdued tints of moderate vigor happen to prevail; nor is it useless, since thereby a definite object is set before us and we have only to seek for means suitable to accomplish it - and it is somewhat remarkable as well as gratifying to the advocates of book-farming to notice the harmony in principle which prevails in the prescription of Loudox, the highest English Agricultural authority, for converting an over-luxuriant wheatfield into productiveness, and that of Monsieur Cappe, French Pomological authority quite as high, for changing an over luxuriant wood branch into fruitfulness - the one would rob the plants of their blades in April by " cutting them off with sheep or even horses;" the other would " pinch early the soft extremities of the shoots on vigorous parts".

I have thought too that Mr. Dowkihg's strawberry problem would admit of solution on this principle. Many varieties tending, in a rich light soil, to that obesity of luxuriance which is imbecility, are kept in moderate vigor by compelling the roots to labor for a living amid pounded soil, which is to them the being pastured on " short commons".

L. Young.

Springdals, Xy., 1851.