In tracing the history of the arts and sciences, we are not unfrequently surprised at the particular, and in some cases very remarkable events or circumstances that have given life and development to certain branches; and in fact this constitutes one of the most in* teresting, if not instructive, features of such a study. Printing, Navigation, Astronomy, the application of steam and electricity, all of which are exercising the most unbounded influence upon the world, have moved forward with various degrees of progress, from indistinct and almost unintelligible glimmerings, to their present amazing development.

For long ages they may have been neglected, overlooked, scarcely spoken of; when all at once, some accidental occurrence, perfectly unimportant in itself - some individual taste or caprice, or perhaps some general and wide-spread necessity, called forth by the changing conditions or pursuits of a class, or a community, induces a spirit of research and inquiry, forming a new epoch from which to date a real intelligent progress. The progressive history of the study of vegetable physiology, is, to the student of nature, no less than to the practical cultivator, replete with interest and instruction; and its future history will be still more so, vastly more so, than the past. The most difficult, and the most important points, yet await a satisfactory solution. This study just begins to take root in American minds, and it might strike into a less genial soil. A necessity has called attention to it - a necessity which every day increases in magnitude, as the interest which has created it becomes wider and deeper.

Necessity is not only " the mother of invention," as the old adage goes, but it is the mother of study and research. In America we have all the ordinary inducements to a study of nature, bestowed upon us with a bountiful find unsparing hand. What other people on earth have been blessed with such a glorious domain, extending over so many degrees of latitude; embracing so many climates, from the frozen north to the tropics; such an almost endless variety of vegetation, from the lofty and powerful oak to the lowly moss?

We are, moreover, a nation of cultivators. Our great pursuit, Agriculture, which is Jar above and beyond all others, in its paramount importance, dooms us to a life among the vegetable productions of the earth; and it is a truth now undisputed, that our success in this pursuit depends no less upon our comprehension of the laws that control and regulate the life of plants, than on our industry in carrying out the practical teachings of experience.

Yet and withal, the science of vegetable physiology has remained up to this period, all but a dead letter amongst us. The ordinary routine of practical agriculture is profitable, and to a great extent successful, without it; but at length a special necessity for its study makes its appearance. A certain branch of culture, under certain circumstances, demands it; cannot be successfully and satisfactorily prosecuted without it; that branch is Fruit trees. They are not practical farmers and gardeners alone, who, in this country, and in these days, are engaged and engaging in fruit and fruit tree culture - but learned and highly cultivated men, from the pulpit, the bar, the press, and all other intellectual pursuits. These men come into the fruit garden and the nursery, not like those who are " to the manor bom," with skillful, practiced hands, and minds overflowing with old fashioned experience, but strangers to everything, and novices in everything; no obstinate dogmas to contend with; all to be sought for and learned. They turn at once to books.

Her they are directed, in an off-hand, practical way, to plant in this manner, and prune in that; the reasons, the principles upon which such practices are based, being seldom touched upon, or if so, in a manner so superficially, or so vaguely, as to be misunderstood by those who have no practical experience to fall back upon. Books, in some cases, too, are opposed to one another, and this puzzles the beginner; so he wisely concludes to go back and examine the fundamental principles upon which all cultural operations depend lie sees an absolute necessity for this, in order to prosecute the work he has undertaken in the same intelligent and discriminating manner to which he had been accustomed in his other pursuits. Hence it is, that the subject of vegetable physiology, principally as regards its bearing upon the pruning and management of fruit trees, is attracting the attention of the most intelligent fruit culturists in all parts of the country. Those who are in any way connected with this pursuit, are well aware of this; and the horticultural journals bear ample testimony to the fact. It cannot, therefore, be considered visionary to anticipate another great good to our country, from our new progress in fruit gardening, in addition to the ordinary benefits we are wont to enumerate.

A good consisting not only in a greatly extended study of nature in the abstract, but in the theory of vegetation in detail; the germination of the seed; the structure and development of the root, the stem, the branch, the bud, and the leaf; the functions of all these parts; their connection with one another, and relative importance to the life, and growth, and fruitfulness of the tree. This is to be the study; and what a fresh, delightful, and imposing aspect it will give to cultivation! How it will raise it up from the condition of a merely toilsome, dull, empirical routine of labor, to be " the inclination of kings, and the choice of philosophers!'1 I therefore rejoice to see this subject taken up by inquiring and intelligent minds. No matter how crude and visionary their first conceptions may appear, nor how much they may misjudge the teachings of the book, they are valuable and important as indicative of "the good time coming." Having acquired some experience, not only in the perusal and examination of theories, as laid down in books, but in putting them to the actual test of practice, I propose to offer a few suggestions that may not be altogether unserviceable to those who are but commencing their studies, investigations, and experiments.

The first point is to obtain as clear an idea as possible, in the present state of knowledge, concerning the organic structure of trees - beginning with the first pair of leaves and radicles, or young roots; to trace the mode in-which the roots spread through the soil, and imbibe food, which is conveyed upwards through the stem into the leaves; how, and by what influences it is then elaborated and prepared to enter into the formation of new parts; to trace the successive accumulation or growth of parts; of layer of wood on the top of layer; of branch upon branch; the formation of buds, the expansion of leaves, etc.

Having thus studied the general subject, the student will be prepared to understand and appreciate the operations by which all these parts are controlled, and made subservient to certain specific ends. He will comprehend why the cutting back of the first seasons' growth of a young tree increases its diameter at the base, and produces branches there by simply changing the locality of the most active point of growth. Why pruning during the inactive season of growth promotes vigor, and in the growing season diminishes it. Why root pruning affects the vigor and productiveness of trees, and under what circumstances growth and bearing are respectively promoted or retarded. The effect of moisture and dryness; heat and cold; light and shade, upon all parts of the tree; and the various operations recommended to control and regulate these elements.

Then comes the study in detail of the various forms or modifications of the same organs, and their comparative forces or functions in the general life of the tree. For instance, we have roots of various kinds on the same tree; large woody roots and delicate fibres. Branches and shoots of various degrees of vigor, and of various purpose in the economy of the plant. Buds, varying in form, purpose, position and force.

These, all, not only in nomenclature, but in their general and particular influence and relative connection, must be carefully studied.

Again, we come to the study of the different characters presented by different genera and species of trees; differences in their general nature, modes of growth and of bearing, as for instance, between the apple and the peach; the pear and the cherry, etc. This is a most important branch of the study, for it teaches us an all important sense of this discrimination in the treatment of trees. For instance, the peach tree, unlike the apple, the pear and many others, produces its fruit on yearling shoots - that is, the fruit buds are formed daring their first season's existence, and blossom and bear the next. This at once suggests the necessity of having always a good supply of healthy annual shoots. In our climate, and in most others, art must come to the aid of nature, in order to ensure this succession of good growth, and hence most authors recommend, and cultivators practice, a sort of pruning which has been termed " shortening-in," which takes away some of the fruit buds and the points of the shoots, and throws the forces of the tree into the strong wood buds towards the base, and these give us strong shoots for the next season, that we could not otherwise obtain.

Unless the mode of growth and bearing of this tree is studied, this operation will not be understood, and hence a very intelligent gentleman, in a recent article on the " theory of pruning," calls this "absurd philosophy," because it excites only one of the forces of the tree.

If he will take the whole subject into calm and careful consideration, he will find it not so absurd. But even after the general differences that exist between genera and species, have been studied, there are still a multitude of conditions in varieties of the same species, that must be observed well in pruning. For instance, all pears do not grow alike; some varieties are low, stout, much disposed to branch, whilst others are just the opposite; some are disposed to bear young, whilst others are tardy; and some productive to a fault, others the reverse; these different forms and habits must be met with appropriate treatment; the mode of pruning that would exactly suit one, might be ruinous to another. It is the case in all species, but he who has mastered the general principles will not experience much difficulty in adapting the treatment to the case. I hope to be able in a short time, if some one more competent does not take it up, to present a classification of varieties of fruit trees, with reference to this last point.

P. B.

Rochester, January, 1893.