"Universal Method" of Adanson. The first author of the system was Bernard de Jussieu, who applied it in the arrangement of the garden of the Trianon, in 1759, though he never published upon it. His nephew, Antoine Laurent de Jussieu, in his Treatise of the Arrangement of the Trianon, gave an account of the principles and orders of his uncle, which he adopted when he succeeded him; and, at a later period, published his Genera Plantarum secundum Ordines Naturales disposita; a work, says Cuvier, which perhaps forms as important an epoch in the sciences of observation, as the Chimie of Lavoisier does in the sciences of experiment. The object of the Jussieus was to obtain a system which should be governed by the natural affinities of the plants, while, at the same time, the characters by which the orders were ostensibly determined, should be as clear, simple, and precise, as those of the best artificial system. The main points in these characters were the number of the cotyledons, and the structure of the seed; and subordinate to this, the insertion of the stamina, which they distinguished as epigynous, perigynous, and hypogynous, according as they were inserted over, about, or under, the germen. And the classes which were formed by the Jussieus, though they have since been modified by succeeding writers, have been so far retained by the most profound botanists, notwithstanding all the new care and new light which have been bestowed upon the subject, as to show that what was done at first, was a real and important step in the solution of the problem. The merit of the formation of this natural method of plants must be divided between the two Jussieus. It has been common to speak of the nephew, Antoine Laurent, as only the publisher of his uncle's work. But this appears, from a recent statement, to be highly unjust. Bernard left nothing in writing but the catalogues of the garden of the Trianon, which he had arranged according to his own views: but these catalogues consist merely of a series of names without explanation or reason added. The nephew, in 1773, undertook and executed for himself the examination of a natural family, the Ranunculacea; and he was wont to relate (as his son informs us) that it Mém. Ac. P. 1774. • Prodromus Flora Penins. Ind. Orient. Wight and Walker-Arnott, Introd. p. XXXV. 8 By Adrien de Jussieu, son of Antoine Laurent, in the Annales des Sc. Nat., Nov. 1834. was this employment which first opened his eyes and rendered him a botanist. In the memoir which he wrote, he explained fully the relative importance of the characters of plants, and the subordination of some to others;—an essential consideration, which Adanson's scheme had failed to take account of. The uncle died in 1777; and his nephew, in speaking of him, compares his arrangement to the Ordines Naturales of Linnæus: "Both these authors," he says, "have satisfied themselves with giving a catalogue of genera which approach each other in different points, without explaining the motives which induced them to place one order before another, or to arrange a genus under a certain order. These two arrangements may be conceived as problems which their authors have left for botanists to solve. Linnæus published his; that of M. de Jussieu is only known by the manuscript catalogues of the garden of the Trianon." It was not till the younger Jussieu had employed himself for nineteen years upon botany, that he published, in 1789, his Genera Plantarum; and by this time he had so entirely formed his scheme in his head, that he began the impression without having written the book, and the manuscript was never more than two pages in advance of the printer's type. When this work appeared, it was not received with any enthusiasm ; indeed, at that time, the revolution of states absorbed the thoughts of all Europe, and left men little leisure to attend to the revolutions of science. The author himself was drawn into the vortex of public affairs, and for some years forgot his book. The method made its way slowly and with difficulty: it was a long time before it was comprehended and adopted in France, although the botanists of that country had, a little while before, been so eager in pursuit of a natural system. In England and Germany, which had readily received the Linnæan method, its progress was still more tardy. There is only one point, on which it appears necessary further to dwell. A main and fundamental distinction in all natural systems, is that of the Monocotyledonous and Dicotyledonous plants; that is, plants which unfold themselves from an embryo with two little leaves, or with one leaf only. This distinction produces its effects in the systems which are regulated by numbers; for the flowers and fruit of the monocotyledons are generally referrible to some law in which the number three prevails; a type which rarely occurs in dicotyledons, these affecting most commonly an arrangement founded on the number five. But it appears, when we attempt to rise towards a natural method, that this division according to the cotyledons is of a higher order than the other divisions according to number; and corresponds to a distinction in the general structure and organization of the plant. The apprehension of the due rank of this distinction has gradually grown clearer. Cuvier conceives that he finds such a division clearly marked in Lobel, in 1581, and employed by Ray as the basis of his classification a century later. This difference has had its due place assigned it in more recent systems of arrangement; but it is only later still that its full import has been distinctly brought into view. Desfontaines discovered that the ligneous fibre is developed in an opposite manner in vegetables with one and with two cotyledons;towards the inside in the former case, and towards the outside in the latter; and hence these two great classes have been since termed endogenous and exogenous. Thus this division, according to the cotyledons, appears to have the stamp of reality put upon it, by acquiring a physiological meaning. Yet we are not allowed to forget, even at this elevated point of generalization, that no one character can be imperative in a natural method. Lamarck, who employed his great talents on botany, before he devoted himself exclusively to other branches of natural history, published his views concerning methods, systems," and characters. His main principle is, that no single part of a plant, however essential, can be an absolute rule for classification; and hence he blames the Jussieuian method, as giving this inadmissible authority to the cotyledons. Roscoe1 further urges that some plants, as Orchis morio, and Limodorum verecundum, have no visible cotyledons. Yet De Candolle, who labored along with Lamarck, in the new edition of the Flore Française, has, as we have already intimated, been led, by the most careful application of the wisest principles, to a system of Natural Orders, of which Jussieu's may be looked upon as the basis; and we shall find the greatest botanists, up to the most recent period, recognizing, and employing themselves in improving, Jussieu's Natural Families; so that in the progress of this part of our knowledge, vague and perplexing as it is, we have no exception to our general aphorism, that no real acquisition in science is ever discarded. Hist. Sc. Nat. ii. 197. 10 Hist. Sc. Nat. i. pp. 196, 290. 11 Sprengel, ii. 296; and, there quoted, Flore Française, t. i. 3, 1778. Mem. Ac. P. 1785. Journ. Hist. Nat. t. i. For Lamarck's Méthode Analytique, see Dumeril, Sc. Nat. i. Art. 390. 12 Roscoe, Linn. Tr. vol. xi. Cuscuta also has no cotyledons. The reception of the system of Jussieu in this country was not so ready and cordial as that of Linnæus. As we have already noticed, the two systems were looked upon as rivals. Thus Roscoe, in 1810," endeavored to show that Jussieu's system was not more natural than the Linnæan, and was inferior as an artificial system: but he argues his points as if Jussieu's characters were the grounds of his distribution; which, as we have said, is to mistake the construction of a natural system. In 1803, Salisbury" had already assailed the machinery of the system, maintaining that there are no cases of perigynous stamens, as Jussieu assumes; but this he urges with great expressions of respect for the author of the method. And the more profound botanists of England soon showed that they could appreciate and extend the natural method. Robert Brown, who had accompanied Captain Flinders to New Holland in 1801, and who, after examining that country, brought home, in 1805, nearly four thousand species of plants, was the most distinguished example of this. In his preface to the Prodromus Flora Nova Hollandiæ, he says, that he found himself under the necessity of employing the natural method, as the only way of avoiding serious error, when he had to deal with so many new genera as occur in New Holland; and that he has, therefore, followed the method of Jussieu; the greater part of whose orders are truly natural, "although their arrangement in classes, as is," he says, "conceded by their author, no less candid than learned, is often artificial, and, as appears to me, rests on doubtful grounds." From what has already been said, the reader will, I trust, see what an extensive and exact knowledge of the vegetable world, and what comprehensive views of affinity, must be requisite in a person who has to modify the natural system so as to make it suited to receive and arrange a great number of new plants, extremely different from the genera on which the arrangement was first formed, as the New Holland genera for the most part were. He will also see how impossible it must be to convey by extract or description any notion of the nature of these modifications: it is enough to say, that they have excited the applause of botanists wherever the science is studied, and that they have induced M. de Humboldt and his fellow-laborers, themselves botanists of the first rank, to dedicate one of their works to him in terms of the strongest admiration." Mr. Brown has also published 13 Linn. Tr. vol. xi. p. 50. 14 Ibid. vol. viii. Roberto Brown, Britanniarum gloriæ atque ornamento, totam Botanices scientiam ingenio mirifico complectenti. &c. special disquisitions on parts of the Natural System; as on Jussieu's Proteacea on the Asclepiadea, a natural family of plants which must be separated from Jussieu's Apocynea:" and other similar labors. We have, I think, been led, by our survey of the history of Botany, to this point;-that a Natural Method directs us to the study of Physiology, as the only means by which we can reach the object. This conviction, which in botany comes at the end of a long series of attempts at classification, offers itself at once in the natural history of animals, where the physiological signification of the resemblances and differences is so much more obvious. I shall not, therefore, consider any of these branches of natural history in detail as examples of mere classification. They will come before us, if at all, more properly when we consider the classifications which depend on the functions of organs, and on the corresponding modifications which they necessarily undergo; that is, when we trace the results of Physiology. But before we proceed to sketch the history of that part of our knowledge, there are a few points in the progress of Zoology, understood as a mere classificatory science, which appear to me sufficiently instructive to make it worth our while to dwell upon them. [2nd Ed.] [Mr. Lindley's recent work, The Vegetable Kingdom (1846), may be looked upon as containing the best view of the recent history of Systematic Botany. In the Introduction to this work, Mr. Lindley has given an account of various recent works on the subject; as Agardh's Classes Plantarum (1826); Perleb's Lehrbuch der Naturgeschichte der Pflanzenreich (1826); Dumortier's Florula Belgica (1827); Bartling's Ordines Naturales Plantarum (1830); Hess's Uebersicht der Phanerogenischen Natürlichen Pflanzenfamilien (1832); Schulz's Natürliches System des Pflanzenreich's (1832); Horaninow's Prima Linea Systematis Natura (1834); Fries's Corpus Florarum provincialium Suecia (1835); Martins's Conspectus Regni Vegetabilis secundum Characteres Morphologicos (1835); Sir Edward F. Bromhead's System, as published in the Edinburgh Journal and other Journals (1836-1840); Endlicher's Genera Plantarum secundum Ordines Naturales disposita (1836-1840); Perleb's Clavis Classicum Ordinum et Familiarum (1838); Adolphe Brongniart's Enumération des Genres de Plantes (1843); Meisner's Plantarum vascularium Genera secundum Ordines Naturales digesta (1843); Horaninow's Tetractys Naturæ, seu Systema quinquemembre omnium Naturalium 16 Linn. Tr. vol. x. 1809. 17 Mem. of Wernerian N. H. Soc. vol. i. 1809. |