CHAPTER III. FORMATION OF A SYSTEM OF ARRANGEMENT OF Sect. 1.-Prelude to the Epoch of Casalpinus. THE arrangement of plants in the earliest works some other extraneous circumstance, as in Pliny. This, and the division of vegetables by Dioscorides into aromatic, alimentary, medicinal, vinous, is, as will be easily seen, a merely casual distribution. The Arabian writers, and those of the middle ages, showed still more clearly their insensibility to the nature of system, by adopting an aphabetical arrangement; which was employed also in the Herbals of the sixteenth century. Brunfels, as we have said, adopted no principle of order: nor did his successor, Fuchs. Yet the latter writer urged his countrymen to put aside their Arabian and barbarous Latin doctors, and to observe the vegetable kingdom for themselves; and he himself set the example of doing this, examined plants with zeal and accuracy, and made above fifteen hundred drawings of them.1 The difficulty of representing plants in any useful way by means of drawings, is greater, perhaps, than it at first appears. So long as no distinction was made of the importance of different organs of the plant, a picture representing merely the obvious general appearance and larger parts, was of comparatively small value. Hence we are not to wonder at the slighting manner in which Pliny speaks of such records. who gave such pictures of plants,' he says, 'Crateuas, Dionysius, Metrodorus, have shown nothing clearly, except the difficulty of their undertaking. A picture 1 His Historia Stirpium was published at Basil in 1544. Those may be mistaken, and is changed and disfigured by copyists; and, without these imperfections, it is not enough to represent the plant in one state, since it has four different aspects in the four seasons of the year.' The diffusion of the habit of exact drawing, especially among the countrymen of Albert Durer and Lucas Cranach, and the invention of wood-cuts and copper-plates, remedied some of these defects. Moreover, the conviction gradually arose in men's minds that the structure of the flower and the fruit are the most important circumstances in fixing the identity of the plant. Theophrastus speaks with precision of the organs which he describes, but these are principally the leaves, roots, and stems. Fuchs uses the term apices for the anthers, and gluma for the blossom of grasses, thus showing that he had noticed these parts as generally present. In the next writer whom we have to mention, we find some traces of a perception of the real resemblances of plants beginning to appear. It is impossible to explain the progress of such views without assuming in the reader some acquaintance with plants; but a very few words may suffice to convey. the requisite notions. Even in the plants which most commonly come in our way, we may perceive instances of the resemblances of which we speak. Thus Mint, Marjoram, Basil, Sage, Lavender, Thyme, Dead-nettle, and many other plants, have a tubular flower, of which the mouth is divided into two lips; hence they are formed into a family, and termed Labiata. Again, the Stock, the Wall-flower, the Mustard, the Cress, the Lady-smock, the Shepherd's-purse, have, among other similarities, their blossoms with four petals arranged crosswise; these are all of the order Cruciferæ. Other flowers, apparently more complex, still resemble each other, as Daisy, Marigold, Aster, and Chamomile; these belong to the order Composite. And though the members of each such family may differ widely in their larger parts, their stems and leaves, the close study of nature leads the botanist irresistibly to consider their resemblances as occupying a far more important place than their differences. It is the general establishment of this conviction and its consequences which we have now to follow. The first writer in whom we find the traces of an arrangement depending upon these natural resemblances, is Hieronymus Tragus, (Jerom Bock,) a laborious German botanist, who, in 1551, published a herbal. In this work, several of the species included in those natural families to which we have alluded,2 as for instance, the Labiata, the Cruciferæ, the Compositæ, are for the most part brought together; and thus, although with many mistakes as to such connexions, a new principle of order is introduced into the subject. In pursuing the developement of such principles of natural order, it is necessary to recollect that the principles lead to an assemblage of divisions and groups, successively subordinate, the lower to the higher, like the brigades, regiments, and companies of an army, or the provinces, towns, and parishes of a kingdom. Species are included in Genera, Genera in Families or Orders, and Orders in Classes. The perception that there is some connexion among the species of plants, was the first essential step; the detection of different marks and characters which should give, on the one hand, limited groups, on the other, comprehensive divisions, were other highlyimportant parts of this advance. To point out every successive movement in this progress would be a task of extreme difficulty, but we may note, as the most prominent portions of it, the establishment of the groups which immediately include Species, that is, the formation of Genera; and the invention of a method which should distribute into consistent and distinct divisions the whole vegetable kingdom, that is, the construction of a System. To the second of these two steps we have no difficulty in assigning its proper author. It belongs to Casalpinus, and marks the first great epoch of this 2 Sprengel, i. 270. science. It is less easy to state to what botanist is due the establishment of Genera; yet we may justly assign the greater part of the merit of this invention, as is usually done, to Conrad Gessner of Zurich. This eminent naturalist, after publishing his great work on animals, died of the plague in 1565, at the age of forty-nine, while he was preparing to publish a History of Plants, a sequel to his History of Animals. The fate of the work thus left unfinished was remarkable. It fell into the hands of his pupil, Gaspard Wolf, who was to have published it, but wanting leisure for the office, sold it to Joachim Camerarius, a physician and botanist of Nuremberg, who made use of the engravings prepared by Gessner, in an Epitome which he published in 1586. The text of Gessner's work, after passing through various hands, was published in 1754 under the title of Gessneri Opera Botanica per duo sæcula desiderata, &c., but is very incomplete. The imperfect state in which Gessner left his botanical labours makes it necessary to seek the evidence of his peculiar views in scattered passages of his correspondence and other works. One of his great merits was, that he saw the peculiar importance of the flower and fruit as affording the characters by which the affinities of plants were to be detected; and that he urged this view upon his contemporaries. His plates present to us, by the side of each plant, its flower and its fruit, carefully engraved. And in his communications with his botanical correspondents, he repeatedly insists on these parts. Thus in 1565 he writes to Zuinger concerning some foreign plants which the latter possessed: Tell me if your plants have fruit and flower, as well as stalk and leaves, for those are of much the greater consequence. By these three marks, flower, fruit, and seed,-I find that Saxifraga and Consolida Regalis are related to Aconite.' These characters, derived from the fructification (as the assemblage of flower and fruit is called), 3 Cuvier, Leçons sur l'Hist. des Sciences Naturelles, partie ii. p. 193. 4 Epistolæ, fol. 113a; see also fol. 65 b. are the means by which genera are established, and hence, by the best botanists, Gessner is declared to be the inventor of genera.5 The labours of Gessner in botany, both on account of the unfinished state in which he left the application of his principles, and on account of the absence of any principles manifestly applicable to the whole extent of the vegetable kingdom, can only be considered as a prelude to the epoch in which those defects were supplied. To that epoch we now proceed. Sect. 2.-Epoch of Casalpinus.-Formation of a If any one were disposed to question whether Natural History truly belongs to the domain of Inductive Science; whether it is to be prosecuted by the same methods, and requires the same endowments of mind as those which lead to the successful cultivation of the Physical Sciences, the circumstances under which Botany has made its advance appear fitted to remove such doubts. The first decided step in this study was merely the construction of a classification of its subjects. We shall, I trust, be able to show that such a classification includes, in reality, the establishment of one general principle, and leads to more. But without here dwelling on this point, it is worth notice mus 5 Haller, Biblio Botanica, i. 284. uti patet ex Epistolis ejus posMethodi Botanicæ rationem pri- tremis, et Tabulis per Carmerapervidit;-dari nempe et rium editis.' genera quæ plures species comprehenderent et classes quæ multa genera. Varias etiam classes naturales expressit. Characterem in flore inque semine posuit, &c.— Ranwolfo Socio Epist. Wolf, p. 39. Linnæus, Genera Plantarum, Pref. xiii. ' A fructificatione plantas distinguere in genera, infinitæ sap entiæ placuisse, detexit posterior ætas, et quidem primus, sæculi sui ornamentum, Conradus Gessnerus, Cuvier says (Hist. des Sc. Nat. ze pe, p. 193), after speaking to the same effect, Il fit voir encore que toutes les plantes qui ont des fleurs et des fruits semblables se ressemblent par leurs autres formes, et souvent aussi par leurs propriétés, et que quand on rapproche ces plantes on obtient ainsi une classification naturelle.' I do not know if he here refers to any particular passages of Gessner's work. |