Слике страница
PDF
ePub

since botany began to claim any of the distinctions of science ; at a much later period it was considered as so small a branch of the department of natural history, that it was generally included in it as a subordinate, although a favourite study. Even now it may be correctly wed under the same aspect; but so wonderfully have the branches of this great stock expanded, that botany can be said now to comprehend many ramifications dependent on itself, each of which may occupy and amuse the leisure hours of a long life. Vegetable physiology, the distribution of plants as well as of animals comprehending the principles of classification, descriptive botany, or an examination and description of all the species of which the vegetable kingdom is composed, and even the history of the science, are each of them inquiries of great extent. In descriptive botany, instead of the limit which was once supposed to circumscribe its objects, instead of the ten thousand species which Linnæus, with all his information and in the height of his enthusiasm, believed would comprehend all the existing forms of vegetable life, we will not say, in the language of poetry, that ten thousand times ten thousand are rising up before us, but it is well known that the ascertained species are rapidly approaching to one hundred thousand, and new species, we might almost say new genera if not fainilies, are annually added to the long catalogue of recorded names. This immense multitude, while retaining the distinct and characteristic features of vegetable life, is yet subdivided by strong lines of demarcation into many separate tribes. The first and most obvious division is that which removes from the great mass—though we sometimes begin to doubt which is the larger portion -all those whose organs of reproduction are obscure or hidden, those cryptic races, which the great father of classification supposed to delight in secret wedlock, giving no manifestation of the mysterious law by which their forms are perpetuated, even in many of their modifications affording some support to the unphilosophical doctrines of equivocal or spontaneous generation. This class is itself distributed into several families, the Filices, Musci, Algæ, Lichenes and Fungi of the Linnæan school, each of which has exclusively occupied the attention of distinguished naturalists, and still offers to persevering and successful sagacity, the rewards which science bestows on those who raise the veil that conceals from common observers her arangements and her principles. Even among the phænogamic plants, where the characters are more obvious and intelligible, and the size and structure more conspicuous, the numbers are multiplying so rapidly, that the memory can scarcely pursue them, and the powers of discrimination, if not

lost, would be bewildered were it not for that spirit of system which has arranged and introduced order into this mighty mass, and is constantly endeavouring to trace out the minute but powerful chords which connect the segments together, while it assigns to each portion, to each group, to each individual member or being, its appropriate and characteristic qualities. Yet with all the aids that science can furnish, this division may increase so much, that it will become necessary to distribute the task of examination among many associates, and each, instead of grasping at the whole must be content with viewing distinctly and accurately a limited portion. Perhaps in a short time it will become common even for eminent botanists, to devote themselves to some of those large and prominent groups in the vegetable kingdom, that constitute the natural families or orders, and thus by studying minutely and critically the separate parts, the conjoined labours of many will finally render the whole science more correct, more complete, more distinct, and more harmonious.

Let no one be discouraged because his knowledge, though not his labours will appear to be circumscribed; because he cannot as his predecessors were supposed to do, view the vast domain of nature as well in its minute details as in its general outlines. It is not in one department only that the march of science is moving on, as if in an interminable progress. Audax Japeti genus, the aspiring race of inan is always aiming at objects that seem beyond its powers. By these efforts to compass the unattainable, it is perpetually advancing, and though it is now become arduous even to reach the bounds which have already been explored, yet the humbler aspirant if he do not labour to extend those bounds, to become himself a discoverer, may hope to examine carefully and accurately the space which has already been traversed. In every branch of knowledge, in all, at least, which depend on facts for their support, the increase and improvement has been great and rapid. In every department of natural history, the same results which we have noticed in botany are also perceived. Zoology is no longer the study of one individual; quadrupeds, and birds, and fish, and insects, are become distinct pursuits. Even the different orders of insects, as of vegetables, have attracted and fully occupied different observers, and their forms, and habits, and splendid drapery have been noted and delineated, until the imagination is almost become wearied with contemplating the boundless variety of organized beings, and the variety scarcely less boundless of habits, instincts and qualities. Let no one, we repeat it, be discouraged if in this wide theatre his occupation

and researches should appear to be more restricted. He profits by the labours of all; and if he can no longer bestow a very minute inspection upon each member of each group, where “ numbers without number” crowd around him, yet his general views will be more correct and satisfactory, his generalizations more true and more profound, as they will be derived from the determination of a greater number of individual facts. By the division and subdivision of research, the myriads, whom no one person could examine and describe, will all fall to the allotment of some inquirer, and be made to afford some items to the general mass of human knowledge.

Nor should the perpetual expansion of this circumference deter the lover of natural history from engaging in its study. It should rather be a gratification to him that his occupations will

interminable, that curiosity, in its own nature insatiable, shall be supplied by fountains in themselves exhaustless. In no pursuit, perhaps, in which man engages, does he enter with so pure and disinterested an enthusiasm, with such devoted and exclusive ardour. There is none in which successful results appear to give more unmingled pleasure. Labor ipse voluptas, is the motto which should always be ins ribed on his banner. When we have seen the wish expressed, that the valetudinarian could find “ some light and pleasant mental pursuit that can be taken up and relinquished at pleasure, without producing much excitement," we have been constantly reminded of the resources which natural history could supply. How often, and how easily could its allurements make the dyspeptic forget his unquiet feelings, the infirm his lassitude and distress; they might even cause the fretful traveller to cease murmuring at rough roads, lost breakfasts or forgotten luncheons; or smooth the bed of him who wanders amidst the unbroken silence and deep solitudes of nature.

Amidst this ample range which botany now opens to our researches, it will be proper to limit our own speculations. We shall, therefore, at present, confine our observations to the arrangement and distribution of plants and their subsequent description, and in a country where these subjects have occupied but little of the public attention, we may, we hope, be excused, if we indulge in some preliminary discussion, and offer some remarks which, under other circumstances, might appear inappropriate if not superfluous.

We have formerly remarked,* " that it is the great aim of natural history, when considered as a science, to group and

* Southern Review No. 4, p. 413. VOL. IV.NO. 8.

60

to arrange all the productions of nature, all modifications of being, on such principles, that the individuals of each group shall be connected by common qualities, by composition, by struct:ire, by habit, and as an alınost necessary consequence, by their properties and uses." That those, and only those species in each department of nature, may be thrown together which are intimately allied, so that the qualities which are ascertained to belong to one member of any group, may be expected as a practical corollary to extend through the whole series.

The early systems of natural history were in this respect unquestionably imperfect. The examination of natural bodies had generally been superficial, the comparative structure of animals had not been studied; chemistry, even now imperfect, was then but a series of crude and hypothetical opinions, and the fundamental principles on which the science ought to rest, had not been thoroughly investigated. Many distinguished naturalists, because under such circumstances, all could not be accomplished; perhaps all may never be accomplished—which theory represents as desirable, objected to system altogether, and proposed that the objects of nature should be considered individually and in detail.

There was a period when the discoveries in natural history were so limited, that such an effort might perhaps have been successful. It is almost unnecessary to remark how impracticable in the present state of science, would be such an attempt. If every quadruped, bird, reptile, fish, insect, and the still more imperfect animals; if every vegetable, now known, was to be considered and described as an independent and isolated being, and the characters which it may possess in common with some ascertained class, and order, and genus, in the great family to which it apparently belongs, are to be forever repeated, what termination could be proposed to such multiplied and unnecessary labours. How impossible to find minds so comprehensive, or memories so tenacious as to embrace and retain, without some technical aid, the varied and still unnumbered forms of nature. Who could pursue or connect his own studies without those general views which associate together multitudes of individuals by some common characters? Who could follow or comprehend the labours of another ? Even if these characters were at first selected without a sufficient examination of their comparative value, they still served to mark and discriminate many species. The cloven hoof, the horn, the canine tooth, the webbed foot, are all conspicuous and valuable features; if they united species, not in all respects intimately allied, they, at

least, distinguished those which possessed some one common and prominent character.

If these discussions have lost some of their ancient interest, if upon many of the speculations which engaged the thoughts of a past generation, time appear to have past his irreversible sentence,it is yet sometimes beneficial to review these opinions, because it is not uncommon to find important truths mingled with the most inconsiderate errors, and because hidden truths have frequently been disclosed and established in the controversies, which have arisen on theories and doctrines in themselves inaccurate.

Thus the discussions on this subject were productive of unexpected benefit. They provoked and occasioned a critical examination of all existing systems of classification, and of all which at any time had been proposed, and led, or will lead to a proper estimate of the value of the different characters which have been or perhaps may be employed in their construction. The founders or reformers of systems, at first generally adopted some one principle or character, or the combination of a few as the basis of their arrangements. Thus, in the classification of vegetables Magnol founded a system on the calyx or outer covering of the flower; Tournefort on the corolia ; Linnæus on the number and connexion of the stamens and styles; Jussieu on the structure of the seed and on the position rather than the number of stamens. In entomology, Linnæus arranged insects according to the number and structure of their wings, Fabricius principally from their mandibles. Birds have been classed from their bills or their claws; and minerals either by composition, or external characters, or crystalline form. The foundations of these systems have all been contested, and these investigations have contributed to a gradual and progressive reformation. They unfolded the principles on which the true and natural arrangements of natural history must ultimately rest, even if artificial systems should for a long time be partially retained.

We have spoken of systems, as natural or artificial, let us consider more distinctly the principles on which these two modes of classification are founded. One is established on the agreements and harmonies of internal structure, the other on the peculiarities or discrepancies of external form; one required to embrace all the analogies of organized beings, the other only to point out the most striking and permanent distinctions. It is the aim of a natural arrangement to place together those which agree in all their important and fundamental characters. Not one organ, but every organ and function,

« ПретходнаНастави »