« ZurückWeiter »
having or not having been heretofore described, can be readily and accurately ascertained, it is not to this day, and perhaps never will be surpassed. It would not, therefore, be readily abandoned, for one requiring more minute and comprehensive and accurate research; to beginners more obscure and difficult, and consequently uncertain, even if the arrangements of the latter are more philosophical, and the knowledge obtained finally more complete. It appears to us, not improbable, that for a long time to come, a practical acquaintance with plants, will: first be acquired through the few and simple elements of the Linnæan system, and then each plant will be arranged and studied more profoundly in connexion with those other species to which it is naturally allied.
In the second place, there were, if we may be permitted to say so, some defects in the system, perhaps, we should rather say, in its exposition, which strengthened the objections made to it as one for common use. Bernard Jussieu first distributed all plants into seven classes. The Acotyledones, having no stamens; the Monocotyledones and Dicotyledones, each into three classes, with stamens hypogynous, perigynous or epigynous. A. L. Jussieu, to lessen the accumulation of orders in these classes, made use principally of the corolla, whether present or absent, whether monopetalous or polypetalous, to subdivide the Dicotyledonous plants into ten classes, and formed an eleventh of the plants, in which the sterile and fertile florets are essentially distinct, as in the Euphorbiaceæ, Amentaceæ, Coniferæ, &c.; these, with the four other classes, formed fifteen in the whole. Still, however, this, if it has lessened the inconvenience, has not removed the objection: The orders in each class have now no natural connexion, they are held together by artificial ligaments, by the position of the stamens and the structure of the corolla, by characters which are considered by the author himself, as of secondary value. Hence, all who have attempted to modify this system, have only endeavoured, and as yet unsuccessfully, to arrange the orders in a natural and symmetrical series, and to establish other classes or leading divisions of the orders. But the more profoundly we study the arrangements of nature, the more sensibly we perceive, as remarked long since by Linnæus, that the vegetable as every other kingdom of nature, resembles a map rather than a chain, that it is composed of groups of kindred genera, surrounded on every side with occasional intervals by other groups, each connected on different points to distinct and distant families, while, perhaps, a single isolated genus interposes and serves on some of these points, as the connecting link. Whenever we attempt to arrange the orders, we find that there is no
successive series, that in truth, the vegetable kingdom forms a systein of orders, not of classes.
In the third place, it may, perhaps, be said with truth, that the difficolties of this system were at first increased by the caution, if not timidity, with which it was developed. Its own principles were not carried to their full and legitimate results. Bernard Jussieu did not establish a great many orders, and A. L. Jussieu, with something like a fondness for even numbers, increased these orders in his “Genera Plantarum,”! in 1789, exactly to one hundred. In consequence, however, of this limitation, the orders of Jussieu contained many discordant materials, some of them were really not as strictly natural as some of the classes of Linnæus. There appeared at first a great anwillingness to take a single genus, a single plant, perhaps, as the type of an order; an apprehension that the system might be injured, at least as a practical one, by too great a multiplication of families. Yet on this point there can and ought to be no hesitation. If nature has chosen not to limit her models or types, our systems cannot restrict them; and if a thousand orders shall be necessary to exhibit or contain all the types which the vegetable kingdom unfolds, to a thousand orders, every systein which professes to be founded on those types, must be carried. In this respect, the arrangement of Jussieu has already undergone soine beneficial changes. In the last tables we have seen, the number has been increased to one hundred and sixty-four; and this modification and, as we believe, improvement, is still in progress. In the “Theorie Elémentaire de la Botanique” of De Candolle, published in 1819, the number of orders then given was one hundred and sixty-one. In the Prodromus before us, as far as published, the first sixty-six orders have been, by subdivision and by the interposition of new orders, extended to ninety, so that they will, probably, exceed two hundred before the prodromus shall be completed, and even of the orders as published in this work, many might still, we think, have been advantageously divided.* We have long held the opinion, limited as our opportunities of judging have been, that the families in this system must approach five hundred, before it will form a perfect and consistent exhibition of the vegetable kingdom. We think on this question there should be no compromise. No argument ab inconvenienti, should be permitted to interfere with an arrangement professing to be based on fixed and determinate principles. Every plant which has no associate in any estab
Let the Nelumboneæ and the Nymphiaceæ—the Cleomeæ and the Cappa. reæ--the Violeæ and Sauvageæ—the tribes of the Byttneriaceæ, and of the Terastræmiaceæ, to go no further, be accurately compared.
lished order, ought, however it may lead to the multiplication of these divisions, to have a place of its own.
If we now for a moment advert to the principles of this system, it will appear that it is not so much to any one feature or character, as to the judicious combination of many, that it is indebted for its excellence. Yet its leading and essential principle is, after all, one of secondary value. It is not derived from the embryo itself, its structure, form and position, but on the cotyledons, the special organs with which the einbryo is furnished, to aid in its developement. The absence or presence of this organ forms two large or primary divisions; while among the plants possessing this organ, the number, one, two or many, still constitutes further marks of separation; the position and direction of the embryo, the perisperm and other peculiarities of the seed break again these large masses. Still, however, the plants in each division are far too numerous and dissimilar, and all the known and used characters of the seed will not separate them into well-defined orders. The position of the stamens, the presence or absence of a corolla, its structure where present, the presence or absence of a calix, are all called in.to subdivide to a sufficient degree, the whole vegetable kingdom, and to collect into distinct groups, those which have features truly uniform, and easily recognised. Will human researches lead no further? Will the profound investigations of nature never , carry our knowledge to those deep-seated and mysterious principles, which, existing in the embryo, possess within themselves, even from the dawn of existence, before the unfolding of the first organs of active life, the perfect archetype of all their future forms and modes of being. Even in the germ, the future ens, whether plant or animal, perfect, but not yet sensible to our eyes or our understandings, exists in beautiful, though veiled and hidden symmetry. In every seed the distinct image, with all its peculiar and appropriate characters, is present, and with a clearer ken than we now possess, might be perceived at one view, and not ascertained, as with us, by its slow and gradual developement, Will the glorious discoveries of science never go back to those obscure and secret types? Will man never be permitted to view, even in their first elements, the arrangements of all created forms; in their first movements, the adaptation of all beings and parts of beings to their appointed ends; and to trace to their final results, the beneficent and sublime harmony of nature.
The work we have prefixed to this article, is the first great effort which has been made to arrange all the known plants of the globe, according to the system of Jussięu. It is upwards of
two hundred and forty years since Caspar Bauhin, in his Pinax, attempted to collect in one work, all the plants which had been described by all preceding botanists, and to present, embodied as it were in one tablet, a representation of the vegetable kingdom. This effort was not only laborious, (it remained incomplete after forty years of assiduous toil) but from the insufficient modes and systems under which plants had been described, and the consequent uncertainty in which they were still involved, was altogether unsatisfactory. The same causes obstrueted every similar attempt that was made, before some vniform plan of describing plants had been adopted. The first successful effort, after botany may be considered as a science, to describe in one work the plants of all countries, was, as we have already noticed, the “Species Plantarum” of Linnæus, published in 1753—maximum opus et eternum, as it was well styled by Haller. A second edition was published in 1762, each of these was in two volumes. In subsequent editions, it was, of necessity, greatly enlarged. Willdenow commenced his celebrated edition in 1797, and, at his death, had completed ten parts or volumes, extending to the ferns, inclusively. The remaining orders of the cryptogamic plants have never been published. The prodigious accessions which have been made to botany, since the commencement of the present century-accessions which became conspicuously manifest in the concluding volumes of Willdenow, appeared to deter persons for some time from encountering the immense labour which a new edition, however much called for, would require. At length Roemer and Schultes commenced this task, and their edition of the “Species Plantarum,” though, perhaps, somewhat retarded by the death of one of the associates, is still in progress. In the meantime, those who had adopted the system of Jussieu, had done nothing but publish monographs of particular orders, or had applied the system to the Flora of one or two countries, until at length, the great enterprize of combining in their proper orders, all the plants which had been discovered, and whose numbers were daily augmenting, was undertaken by the author of the work before us.
No man in Europe could have come better prepared to this arduous undertaking. The life of M. De Candolle has been devoted to the study of botany. He was distinguished among the eminent men of France for his sagacity, perseverance and attainments. Besides many dissertations on subjects connected with this science, and on different genera and families of plants, he had published as a preparatory exercise, a "Flore Française,” which has passed through several editions. He was for some time Professor of Botany at Montpellier, and when exiled from France,
on the restoration of the Bourbons, he returned to Geneva, his native city, and received immediately the appointment of Professor of Botany, which he still retains. In 1813, he published his “Théorie Elémentaire de la Botánique,” of which a second edition appeared in 1819. In this work, he first announced his intention of preparing a new Pinax, to which he devoted his future labours, and in 1818, be published “Regoi Vegetabilis Systema Naturale,” volume first, which in 1821, was followed by a second volume. In this elaborate work, a-full view was intended to be given of every order and genus of plants; detailed descriptions of each species, and a complete exhibition of its synonymes and bistory, from the earliest times. It is greatly to be regretted, that this magnificent plan could not be completed by the efforts of many, if not practicable by the labours of one. Eight years, however, had elapsed between the first andouncement of the work and the publication of the second volume-eight years, apparently, had been consumed in completing the description and history of eleven orders, for only that number are contained in the two volumes. It requires but a short calculation to show, that at the same rate much more than a century would be required to complete the work. This proud monument to the science of botany will, perhaps, therefore, never be finished. It is now suspended if not abandoned ; and in 1824, there appeared the first volume of the present “Prodromus ;” the second in 1825, the third in 1828. 'In this epitome, only the characters of the orders and the essential characters of the genera and species are given, and, in general, no other synonymes than that of the author who has been followed, or who is relied on as an authority. The first volume contains fifty-four orders, the second only ten, for the very extensive family of the Leguminosæ occupies, even in this condensed form, two-thirds of the volume, and the Rosaceæ one-half of the remaining third ; the third volume contains twenty-six orders.
On the fundamental principles of his classification, we think our readers will be gratified to hear briefly the exposition of M. De Candolle himself:
“I will explain here in few words the characters of these great classes, and the series of families of which they are composed.
“ Let us consider at first the whole vegetable kingdom, and endeavour to apply the principles we have already stated, to divide it into general classes, either according to the functions of nutrition or those of reproduction.