finished 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 labors, 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), are the means by which genera are established, and hence, by the best botanists, Gessner is declared to be the inventor of genera.5 5 Haller, Biblio Botanica, i. 284. Methodi Botanicæ rationem primus pervidit ;-dari nempe et genera quæ plures species comprehenderent et classes quæ multa genera. Varias etiam classes naturales expressit. Characterem in flore inque semine posuit, &c.-Rauwolfio Socio Epist. Wolf, p. 39. Linnæus, Genera Plantarum, Pref. xiii. "A fructificatione plantas distinguere in genera, infinitæ sapientiæ placuisse, detexit posterior ætas, et quidem primus, sæculi sui ornamentum, Conradus Gessnerus, uti patet ex Epistolis ejus postremis, et Tabulis per Carmerarium editis." Cuvier says (Hist. des Sc. Nat. 2e 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 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. The labors 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 System of Arrange ment. 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 that the person to whom we owe this classification, Andreas Casalpinus of Arezzo, was one of the most philosophical men of his time, profoundly skilled in the Aristotelian lore which was then esteemed, yet gifted with courage and sagacity which enabled him to weigh the value of the Peripatetic doctrines, to reject what seemed error, and to look onwards to a better philosophy. "How are we to understand,” he inquires, "that we must proceed from universals to particulars (as Aristotle directs), when particulars are better known ?” Yet he treats the Master with deference, and, as has been observed,” we see in his great botanical work deep traces of the best features of the Aristotelian school, logic and method; and, indeed, in this work he frequently refers to his Quæstiones Peripateticæ. His book, entitled De Plantis libri xvi. appeared at Florence in 1583. The aspect under which his task presented itself to his mind appears to me to possess so much interest, that I will transcribe a few of his reflections. After speaking of the splendid multiplicity of the productions of nature, and the confusion which has hitherto prevailed among writers on plants, * Quæstiones Peripateticæ, (1569,) lib. i. quæst. i. 7 Cuvier, p. 198. 8 the growing treasures of the botanical world; he adds, "In this immense multitude of plants, I see that want which is most felt in any other unordered crowd: if such an assemblage be not arranged into brigades like an army, all must be tumult and fluctuation. And this accordingly happens in the treatment of plants: for the mind is overwhelmed by the confused accumulation of things, and thus arise endless mistake and angry altercation." He then states his general view, which, as we shall see, was adopted by his successors. "Since all science consists in the collection of similar, and the distinction of dissimilar things, and since the consequence of this is a distribution into genera and species, which are to be natural classes governed by real differences, I have attempted to execute this task in the whole range of plants;-ut si quid pro ingenii mei tenuitate in hujusmodi studio profecerim, ad communem utilitatem proferam." We see here how clearly he claims for himself the credit of being the first to execute this task of arrangement. 9 After certain preparatory speculations, he says, "Let us now endeavor to mark the kinds of plants by essential circumstances in the fructification." He then observes, "In the constitution of organs three things are mainly important-the number, the position, the. figure." And he then proceeds to exemplify this: "Some have under one flower, ONE seed, as Amygdala, or ONE seed-receptacle, as Rosa or Two seeds, as Ferularia, or Two seed-receptacles, as Nasturtium; or three, as the Tithymalum kind have THREE seeds, the Bulbacea THREE receptacles; or four, as Marrubium, FOUR seeds, Siler FOUR receptacles; or more, as Cicoracea, and Acanaceae have MORE seeds, Pinus, MORE receptacles." It will be observed that we have here ten classes made out by means of number alone, added to the consideration of whether the seed is alone in its covering, as in a cherry, or contained in a receptacle with several others, as in a berry, pod, or capsule. Several of these divisions are, however, further subdivided according to other circumstances, and especially according as the vital part of the seed, which he called the heart (cor1o), is situated in the upper or lower part of the seed. As our object here is only to indicate the principle of the method of Cæsalpinus, I need not further dwell on the details, and still less on the defects by which it is disfigured, as, for instance, the retention of the old distinction of Trees, Shrubs, and Herbs. Dedicatio, a 2. 9 Lib. i. c. 13, 14. 10 Corculum of Linnæus. 13 15 To some persons it may appear that this arbitrary distribution of the vegetable kingdom, according to the number of parts of a particular kind, cannot deserve to be spoken of as a great discovery. And if, indeed, the distribution had been arbitrary, this would have been true; the real merit of this and of every other system is, that while it is artificial in its form, it is natural in its results. The plants which are associated by the arrangement of Cæsalpinus, are those which have the closest resemblances in the most essential points. Thus, as Linnæus says, though the first in attempting to form natural orders, he observed as many as the most successful of later writers. Thus his Legumina11 correspond to the natural order Leguminose; his genus Ferulaceum12 to the Umbellata; his Bulbacea13 to Liliacea; his Anthemides1* to the Composita; in like manner, the Boraginea are brought together, and the Labiata. That such assemblages are produced by the application of his principles, is a sufficient evidence that they have their foundation in the general laws of the vegetable world. If this had not been the case, the mere application of number or figure alone as a standard of arrangement, would have produced only intolerable anomalies. If, for instance, Casalpinus had arranged plants by the number of flowers on the same stalk, he would have separated individuals of the same species; if he had distributed them according to the number of leaflets which compose the leaves, he would have had to place far asunder different species of the same genus. Or, as he himself says, 16 "If we make one genus of those which have a round root, as Rapum, Aristolochia, Cyclaminus, Aton, we shall separate from this genus those which most agree with it, as Napum and Raphanum, which resemble Rapum, and the long Aristolochia, which resembles the round; while we shall join the most remote kinds, for the nature of Cyclaminus and Rapum is altogether diverse in all other respects. Or if we attend to the differences of stalk, so as to make one genus of those which have a naked stalk, as the Junci, Cape, Aphacæ, along with Cicoraceæ, Viola, we shall still connect the most. unlike things, and disjoin the closest affinities. And if we note the differences of leaves, or even flowers, we fall into the same difficulty; for many plants very different in kind have leaves very similar, as Polygonum and Hypericum, Ernea and Sesamois, Apium and Ranunculus; and plants of the same genus have sometimes very different 11 Lib. vi. 15 Lib. xi. 12 Lib. vii. 13 Lib. X. 14 Lib. xii. leaves, as the several species of Ranunculus and of Lactuca. Nor will color or shape of the flowers help us better; for what has Vitis in common with Enanthe, except the resemblance of the flower?" He then goes on to say, that if we seek a too close coincidence of all the characters we shall have no Species; and thus shows us that he had clearly before his view the difficulty which he had to attack, and which it is his glory to have overcome, that of constructing Natural Orders. But as the principles of Casalpinus are justified, on the one hand, by their leading to Natural Orders, they are recommended on the other by their producing a System which applies through the whole extent of the vegetable kingdom. The parts from which he takes his characters must occur in all flowering-plants, for all such plants have seeds. And these seeds, if not very numerous for each flower, will be of a certain definite number and orderly distribution. And thus every plant will fall into one part or other of the same system. It is not difficult to point out, in this induction of Casalpinus, the two elements which we have so often declared must occur in all inductive processes; the exact acquaintance with facts, and the general and applicable ideas by which these facts are brought together. Casalpinus was no mere dealer in intellectual relations or learned traditions, but a laborious and persevering collector of plants and of botanical knowledge. "For many years," he says in his Dedication, "I have been pursuing my researches in various regions, habitually visiting the places in which grew the various kinds of herbs, shrubs, and trees; I have been assisted by the labors of many friends, and by gardens established for the public benefit, and containing foreign plants collected from the most remote regions." He here refers to the first garden directed to the public study of Botany, which was that of Pisa," instituted in 1543, by order of the Grand Duke Cosmo the First. The management of it was confided first to Lucas Ghini, and afterwards to Casalpinus. He had collected also a herbarium of dried plants, which he calls the rudiment of his work. "Tibi enim," he in his dedication to Francis Medici, Grand Duke of Etruria, "apud quem extat ejus rudimentum ex plantis libro agglutinatis a me compositum." And, throughout, he speaks with the most familiar and vivid acquaintance of the various vegetables which he describes. says, But Cæsalpinus also possessed fixed and general views concerning the relation and functions of the parts of plants, and ideas of symmetry 17 Cuv. 187. |