« ZurückWeiter »
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 be 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 inscribed on his banner. When we have seen the wish expressed, that the valetudinarian could find some light and pleasant mental pursuit ahat 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 dyspeptie 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 occapied 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.
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 structure, by habit, and as an almost 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, bad not been thoroughly investigated. Many distinguished naturalists, because under such circumstances, all could not be accomplished; perbaps 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 per haps 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 auother? 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 maoy 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 sta mens 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,
and property of each substance must be ascertained and compared. In each division, each group, however it may be denominated, no individual should be admitted in which all the essential characters of the family are not combined. The genera and species into which they are distributed, should all possess the same essential features, with only such modifications as shall not destroy the integrity of the character. Whenever these features begin to vary in a marked degree, the functions to increase or diminish, new groups must be formed, and this series or succession of new tribes must be continued through the whole domain of nature. These
groups can afterwards be thrown into separate and larger associations connected together by fewer elements, and by a smaller number of the most important characters, and this process can be repeated and continued, until they are all resolved; or rather traced upwards by fundamental characters, to one or other of the three primitive forms of sensitive, vegetative or inorganic existence. It is obvious therefore, that such an arrangement requires a profound investigation of the composition and structure of every form and substance, which nature has produced. It must as a consequence very slowly acquire perfection. It calls for the co-operation of every student of natural science. Even if surrounded with difficulties, it should constantly be considered as the chief object of our inquiries, as the final limit of our researches. Linnæus, to whom more than to any individual, natural history has been indebted for its arrangements, almost for its creation as a science, while he constructed and used artiticial systems, because knowledge in his day admitted of no other, yet looked to natural arrangements as the ultimate aim of all our studies. " Methodus naturalis ultimus finis botanices est et erit,” is his strong and pointed expression, and in another place he adds, “ Primum et ultimum hoc in botanicis desideratum est."
Artificial arrangements are generally established upon a few important and permanent features, in which a great number of individuals have been found to agree. They facilitate in the first instance the determination of species, because a smaller number of characters, frequently a single one, is sufficient for this purpose. Their chief value, therefore, is the readiness with which they ewable us to arrange any newly discovered objects among the groups or sections already established, or to recognize any object which has already been described. But they tell us nothing more than the position of any individual in an arrangement in which his essential qualities have not been considered. Their great defect is that they direct the attention too exclusively to
those characters which, in the formation of each method, are employed as the governing or guiding principle. Frequently these become the only object of research. Soinetimes organs or functions, far more important in the scale of existence than those which have been assumed as essential in an artificial classification, are overlooked or disregarded, and we are thus frequently presented not only with an imperfect, but a distorted view of nature. It must, therefore, happen occasionally if not constantly, that these systems connect together forms which are not truly allied, and that their principles are technical and hypothetical, not comprehensive and profound. When in a natural arrangement, the real place of any individual is determined, his nature, his composition, his structure, his habits, his qualities, are at once announced his form
from that of his associates, but his essential attributes must all correspond. When, on the contrary, the place of an individual is assigned in an artificial arrangement, nothing is determined but the fact of his possessing a limited number of peculiar features. While the study of the one then is calculated to convey only a partial and incomplete view of the arrangements and operations of nature, the knowledge of the other requires the investigation of the structure, the functions, the properties, the powers of all created beings; their mutual relations and dependencies; the great principles that connect together the organized and unorganized occupants of the material world; the wisdom that maintains in harmony, and blends into one mighty and glorious plan, so many jarring and discordant elements.
While we make these acknowledgments, however, and admit the inferiority of artificial systems, let us not deny them their due merit. It is of great moment to those engaged in the active pursuits of natural history, that the objects once described, should be readily recognized, and the new species which they themselves may discover, may be placed in some position where they may be easily remembered, and made known to others. Artificial methods afford this convenience at present, in a greater degree than some of those which are now termed natural, because the latter are by no means perfect, and leave great scope for hesitation and uncertainty. Neither should we forget in this discussion the important services which they have rendered to science. It is from the publication and general adoption of good artificial systems, that may be dated the strong impulse given in the middle of the last century to the pursuit of natural history. It was then only that the discoveries of the enterprizing naturalist could be rendered intelligible; that his researches could pervade all nature; that the discrepancies between objects