III. FORMATION OF A SYSTEM OF ARRANGEMENT OF PLANTS…

III. FORMATION OF A SYSTEM OF ARRANGEMENT OF PLANTS

Sect. 1.--Prelude to the Epoch of Cæsalpinus.

THE arrangement of plants in the earliest works was either arbitrary, or according to their use, or 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 alphabetical 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.[36\16] {370}

[Note 36\16: His Historia Stirpium was published at Basil in 1542.]

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. "Those who gave such pictures of plants," he says, "Crateuas, Dionysius, Metrodorus, have shown nothing clearly, except the difficulty of their undertaking. A picture 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 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 Labiatæ. 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 Compositæ. 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 {371} 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,[37\16] as for instance the Labiatæ, 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.

[Note 37\16: Sprengel, i. 270.]

In pursuing the development 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 highly important 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 Cæsalpinus, and marks the first great epoch of this 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[38\16] 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 {372} 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.

[Note 38\16: Cuvier, Leçons sur l'Hist. des Sciences Naturelles, partie ii. p. 193.]

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[39\16] 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.[40\16] {373}

[Note 39\16: Epistolæ, fol. 113 a; see also fol. 65 b.]

[Note 40\16: 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. 2^e p^e, 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 Cæsalpinus.--Formation of a System of Arrangement.

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 Cæsalpinus 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?"[41\16] Yet he treats the Master with deference, and, as has been observed,[42\16] 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, {374} the growing treasures of the botanical world; he adds,[43\16] "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.

[Note 41\16: Quæstiones Peripateticæ, (1569,) lib. i. quæst. i.]

[Note 42\16: Cuvier, p. 198.]

[Note 43\16: Dedicatio, a 2.]

After certain preparatory speculations, he says,[44\16] "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 Bulbaceæ THREE receptacles; or four, as Marrubium, FOUR seeds, Siler FOUR receptacles; or more, as Cicoraceæ, and Acanaceæ have MORE seeds, Pinus, MORE receptacles."

[Note 44\16: Lib. i. c. 13, 14.]

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 (cor[45\16]), 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. {375}

[Note 45\16: Corculum, of Linnæus.]

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 Legumina[46\16] correspond to the natural order Leguminosæ; his genus Ferulaceum[47\16] to the Umbellatæ; his Bulbaceæ[48\16] to Liliaceæ; his Anthemides[49\16] to the Compositæ; in like manner, the Boragineæ are brought together,[50\16] and the Labiatæ. 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, Cæsalpinus 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,[51\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, Cæpe, Aphacæ, along with Cicoraceæ, Violæ, 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 {376} 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 Œnanthe, 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.

[Note 46\16: Lib. vi.]

[Note 47\16: Lib. vii.]

[Note 48\16: Lib. x.]

[Note 49\16: Lib. xii.]

[Note 50\16: Lib. xi.]

[Note 51\16: Lib. i. cap. xii. p. 25.]

But as the principles of Cæsalpinus 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 Cæsalpinus, 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. Cæsalpinus 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,[52\16] 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 Cæsalpinus. He had collected also a herbarium of dried plants, which he calls the rudiment of his work. "Tibi enim," he says, 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.

[Note 52\16: Cuv. 187.]

But Cæsalpinus also possessed fixed and general views concerning the relation and functions of the parts of plants, and ideas of symmetry {377} and system; without which, as we see in other botanists of his and succeeding times, the mere accumulation of a knowledge of details does not lead to any advance in science. We have already mentioned his reference to general philosophical principles, both of the Peripatetics and of his own. The first twelve chapters of his work are employed in explaining the general structure of plants, and especially that point to which he justly attaches so much importance, the results of the different situation of the cor or corculum of the seed. He shows[53\16] that if we take the root, or stem, or leaves, or blossom, as our guide in classification, we shall separate plants obviously alike, and approximate those which have merely superficial resemblances. And thus we see that he had in his mind ideas of fixed resemblance and symmetrical distribution, which he sedulously endeavored to apply to plants; while his acquaintance with the vegetable kingdom enabled him to see in what manner these ideas were not, and in what manner they were, really applicable.

[Note 53\16: Lib. i. cap. xii.]

The great merit and originality of Cæsalpinus have been generally allowed, by the best of the more modern writers on Botany. Linnæus calls him one of the founders of the science; "Primus verus systematicus;"[54\16] and, as if not satisfied with the expression of his admiration in prose, hangs a poetical garland on the tomb of his hero. The following distich concludes his remarks on this writer: Quisquis hic extiterit primos concedet honores Cæsalpine tibi; primaque serta dabit: and similar language of praise has been applied to him by the best botanists up to Cuvier,[55\16] who justly terms his book "a work of genius."

[Note 54\16: Philosoph. Bot. p. 19.]

[Note 55\16: Cuv. Hist. 193.]

Perhaps the great advance made in this science by Cæsalpinus, is most strongly shown by this; that no one appeared, to follow the path which he had opened to system and symmetry, for nearly a century. Moreover, when the progress of this branch of knowledge was resumed, his next successor, Morison, did not choose to acknowledge that he had borrowed so much from so old a writer; and thus, hardly mentions his name, although he takes advantage of his labors, and even transcribes his words without acknowledgement, as I shall show. The pause between the great invention of Cæsalpinus, and its natural sequel, the developement and improvement of his method, is so marked, that I {378} will, in order to avoid too great an interruption of chronological order, record some of its circumstances in a separate section.

Sect. 3.--Stationary Interval.

THE method of Cæsalpinus was not, at first, generally adopted. It had, indeed, some disadvantages. Employed in drawing the boundary-lines of the larger divisions of the vegetable kingdom, he had omitted those smaller groups, Genera, which were both most obvious to common botanists, and most convenient in the description and comparison of plants. He had also neglected to give the Synonyms of other authors for the plants spoken of by him; an appendage to botanical descriptions, which the increase of botanical information and botanical books had now rendered indispensable. And thus it happened, that a work, which must always be considered as forming a great epoch in the science to which it refers, was probably little read, and in a short time could be treated as if it were quite forgotten.

In the mean time, the science was gradually improved in its details. Clusius, or Charles de l'Ecluse, first taught botanists to describe well. "Before him," says Mirbel,[56\16] "the descriptions were diffuse, obscure, indistinct; or else concise, incomplete, vague. Clusius introduced exactitude, precision, neatness, elegance, method: he says nothing superfluous; he omits nothing necessary." He travelled over great part of Europe, and published various works on the more rare of the plants which he had seen. Among such plants, we may note now one well known, the potato; which he describes as being commonly used in Italy in 1586;[57\16] thus throwing doubt, at least, on the opinion which ascribes the first introduction of it into Europe to Sir Walter Raleigh, on his return from Virginia, about the same period. As serving to illustrate, both this point, and the descriptive style of Clusius, I quote, in a note, his description of the flower of this plant.[58\16] {379}

[Note 56\16: Physiol. Veg. p. 525.]

[Note 57\16: Clusius. Exotic. iv. c. 52, p. lxxix.]

[Note 58\16: "Papas Peruanorum. Arachidna, Theoph. forte. Flores elegantes, uncialis amplitudinis aut majores, angulosi, singulari folio constantes, sed ita complicato ut quinque folia discreta videantur, coloris exterius ex purpura candicantis, interius purpurascentis, radiis quinque herbaceis ex umbilico stellæ instar prodeuntibus, et totidem staminibus flavis in umbonem coeuntibus."

He says that the Italians do not know whence they had the plant, and that they call it Taratouffli. The name Potato was, in England, previously applied to the Sweet Potato (Convolvulus batatas), which was the common Potato, in distinction to the _Virginian _Potato, at the time of Gerard's Herbal. (1597?) Gerard's figures of both plants are copied from those of Clusius.

It may be seen by the description of Arachidna, already quoted from Theophrastus, (above,) that there is little plausibility in Clusius's conjecture of the plant being known to the ancients. I need not inform the botanist that this opinion is untenable.]

The addition of exotic species to the number of known plants was indeed going on rapidly during the interval which we are now considering. Francis Hernandez, a Spaniard, who visited America towards the end of the sixteenth century, collected and described many plants of that country, some of which were afterwards published by Recchi.[59\16] Barnabas Cobo, who went as a missionary to America in 1596, also described plants.[60\16] The Dutch, among other exertions which they made in their struggle with the tyranny of Spain, sent out an expedition which, for a time, conquered the Brazils; and among other fruits of this conquest, they published an account of the natural history of the country.[61\16] To avoid interrupting the connexion of such labors, I will here carry them on a little further in the order of time. Paul Herman, of Halle, in Saxony, went to the Cape of Good Hope and to Ceylon; and on his return, astonished the botanists of Europe by the vast quantity of remarkable plants which he introduced to their knowledge.[62\16] Rheede, the Dutch governor of Malabar, ordered descriptions and drawings to be made of many curious species, which were published in a large work in twelve folio volumes.[63\16] Rumphe, another Dutch consul at Amboyna,[64\16] labored with zeal and success upon the plants of the Moluccas. Some species which occur in Madagascar figured in a description of that island composed by the French Commandant Flacourt.[65\16] Shortly afterwards, Engelbert Kæmpfer,[66\16] a Westphalian of great acquirements and undaunted courage, visited Persia, Arabia Felix, the Mogul Empire, Ceylon, Bengal, Sumatra, Java, Siam, Japan; Wheler travelled in Greece and Asia Minor; and Sherard, the English consul, published an account of the plants of the neighborhood of Smyrna. {380}

[Note 59\16: Nova Plantarum Regni Mexicana Historia, Rom. 1651, fol.]

[Note 60\16: Sprengel, Gesch. der Botanik, ii. 62.]

[Note 61\16: Historia Naturalis Brasiliæ, L. B. 1648, fol. (Piso and Maregraf).]

[Note 62\16: Museum Zeylanicum, L. B. 1726.]

[Note 63\16: Hortus Malabaricus, 1670-1703.]

[Note 64\16: Herbarium Amboinense, Amsterdam, 1741-51, fol.]

[Note 65\16: Histoire de la grande Isle Madagascar, Paris, 1661.]

[Note 66\16: Amœnitates Exoticæ, Lemgov. 1712. 4to.]

At the same time, the New World excited also the curiosity of botanists. Hans Sloane collected the plants of Jamaica; John Banister those of Virginia; William Vernon, also an Englishman, and David Kriege, a Saxon, those of Maryland; two Frenchmen, Surian and Father Plumier, those of Saint Domingo.

We may add that public botanical gardens were about this time established all over Europe. We have already noticed the institution of that of Pisa in 1543; the second was that of Padua in 1545; the next, that of Florence in 1556; the fourth, that of Bologna, 1568; that of Rome, in the Vatican, dates also from 1568.

The first transalpine garden of this kind arose at Leyden in 1577; that of Leipzig in 1580. Henry the Fourth of France established one at Montpellier in 1597. Several others were instituted in Germany; but that of Paris did not begin to exist till 1626; that of Upsal, afterwards so celebrated, took its rise in 1657, that of Amsterdam in 1684. Morison, whom we shall soon have to mention, calls himself, in 1680, the first Director of the Botanical Garden at Oxford.

[2nd Ed.] [To what is above said of Botanical Gardens and Botanical Writers, between the times of Cæsalpinus and Morison, I may add a few circumstances. The first academical garden in France was that at Montpellier, which was established by Peter Richier de Belleval, at the end of the sixteenth century. About the same period, rare flowers were cultivated at Paris, and pictures of them made, in order to supply the embroiderers of the court-robes with new patterns. Thus figures of the most beautiful flowers in the garden of Peter Robins were published by the court-embroiderer Peter Vallet, in 1608, under the title of Le Jardin du Roi Henry IV. But Robins' works were of great service to botany; and his garden assisted the studies of Renealmus (Paul Reneaulme), whose Specimen Historiæ Plantarum (Paris, 1611), is highly spoken of by the best botanists. Recently, Mr. Robert Brown has named after him a new genus of Irideæ (RENEALMIA); adding, "Dixi in memoriam PAULI RENEALMI, botanici sui ævi accuratissimi, atque staminum primi scrutatoris; qui non modo eorum numerum et situm, sed etiam filamentorum proportionem passim descripsit, et characterem tetradynamicum siliquosarum perspexit." (Prodromus Floræ Novæ Hollandiæ, p. 448.)

The oldest Botanical Garden in England is that at Hampton Court, founded by Queen Elizabeth, and much enriched by Charles II. and William III. (Sprengel, Gesch. d. Bot. vol. ii. p. 96.)]

In the mean time, although there appeared no new system which {381} commanded the attention of the botanical world, the feeling of the importance of the affinities of plants became continually more strong and distinct.

Lobel, who was botanist to James the First, and who published his Stirpium Adversaria Nova in 1571, brings together the natural families of plants more distinctly than his predecessors, and even distinguishes (as Cuvier states,[67\16]) monocotyledonous from dicotyledonous plants; one of the most comprehensive division-lines of botany, of which succeeding times discovered the value more completely. Fabius Columna,[68\16] in 1616, gave figures of the fructification of plants on copper, as Gessner had before done on wood. But the elder Bauhin (John), notwithstanding all that Cæsalpinus had done, retrograded, in a work published in 1619, into the less precise and scientific distinctions of--trees with nuts; with berries; with acorns; with pods; creeping plants, gourds, &c.: and no clear progress towards a system was anywhere visible among the authors of this period.

[Note 67\16: Cuv. Leçons, &c. 198.]

[Note 68\16: Ib. 206.]

While this continued to be the case, and while the materials, thus destitute of order, went on accumulating, it was inevitable that the evils which Cæsalpinus had endeavored to remedy, should become more and more grievous. "The nomenclature of the subject[69\16] was in such disorder, it was so impossible to determine with certainty the plants spoken of by preceding writers, that thirty or forty different botanists had given to the same plant almost as many different names. Bauhin called by one appellation, a species which Lobel or Matheoli designated by another. There was an actual chaos, a universal confusion, in which it was impossible for men to find their way." We can the better understand such a state of things, from having, in our own time, seen another classificatory science, Mineralogy, in the very condition thus described. For such a state of confusion there is no remedy but the establishment of a true system of classification; which by its real foundation renders a reason for the place of each species; and which, by the fixity of its classes, affords a basis for a standard nomenclature, as finally took place in Botany. But before such a remedy is obtained, men naturally try to alleviate the evil by tabulating the synonyms of different writers, as far as they are able to do so. The task of constructing such a Synonymy of botany at the period of which we speak, was undertaken by Gaspard Bauhin, the brother of John, but nineteen years younger. This work, the Pinax Theatri Botanici, was printed {382} at Basil in 1623. It was a useful undertaking at the time; but the want of any genuine order in the Pinax itself, rendered it impossible that it should be of great permanent utility.

[Note 69\16: Ib. 212.]

After this period, the progress of almost all the sciences became languid for a while; and one reason of this interruption was, the wars and troubles which prevailed over almost the whole of Europe. The quarrels of Charles the First and his parliament, the civil wars and the usurpation, in England; in France, the war of the League, the stormy reign of Henry the Fourth, the civil wars of the minority of Louis the Thirteenth, the war against the Protestants and the war of the Fronde in the minority of Louis the Fourteenth; the bloody and destructive Thirty Years' War in Germany; the war of Spain with the United Provinces and with Portugal;--all these dire agitations left men neither leisure nor disposition to direct their best thoughts to the promotion of science. The baser spirits were brutalized; the better were occupied by high practical aims and struggles of their moral nature. Amid such storms, the intellectual powers of man could not work with their due calmness, nor his intellectual objects shine with their proper lustre.

At length a period of greater tranquillity gleamed forth, and the sciences soon expanded in the sunshine. Botany was not inert amid this activity, and rapidly advanced in a new direction, that of physiology; but before we speak of this portion of our subject, we must complete what we have to say of it as a classificatory science.

Sect. 4.--Sequel to the Epoch of Cæsalpinus. Further Formation and Adoption of Systematic Arrangement.

SOON after the period of which we now speak, that of the restoration of the Stuarts to the throne of England, systematic arrangements of plants appeared in great numbers; and in a manner such as to show that the minds of botanists had gradually been ripening for this improvement, through the influence of preceding writers, and the growing acquaintance with plants. The person whose name is usually placed first on this list, Robert Morison, appears to me to be much less meritorious than many of those who published very shortly after him; but I will give him the precedence in my narrative. He was a Scotchman, who was wounded fighting on the royalist side in the civil wars of England. On the triumph of the republicans, he withdrew to France, when he became director of the garden of Gaston, Duke of Orléans at Blois; and there he came under the notice of our Charles {383} the Second; who, on his restoration, summoned Morison to England, where he became Superintendent of the Royal Gardens, and also of the Botanic Garden at Oxford. In 1669, he published Remarks on the Mistakes of the two Bauhins, in which he proves that many plants in the Pinax are erroneously placed, and shows considerable talent for appreciating natural families and genera. His great systematic work appeared from the University press at Oxford in 1680. It contains a system, but a system, Cuvier says,[70\16] which approaches rather to a natural method than to a rigorous distribution, like that of his predecessor Cæsalpinus, or that of his successor Ray. Thus the herbaceous plants are divided into climbers, leguminous, siliquose, unicapsalar, bicapsular, tricapsular, quadricapsular, quinquecapsular; this division being combined with characters derived from the number of petals. But along with these numerical elements, are introduced others of a loose and heterogeneous kind, for instance, the classification of herbs as lactescent and emollient. It is not unreasonable to say, that such a scheme shows no talent for constructing a complete system; and that the most distinct part of it, that dependent on the fruit, was probably borrowed from Cæsalpinus. That this is so, we have, I think, strong proof; for though Morison nowhere, I believe, mentions Cæsalpinus, except in one place in a loose enumeration of botanical writers,[71\16] he must have made considerable use of his work. For he has introduced into his own preface a passage copied literally[72\16] from the dedication of Cæsalpinus; which passage we have already quoted (p. 374,) beginning, "Since all science consists in the collection of similar, and the distinction of dissimilar things." And that the mention of the original is not omitted by accident, appears from this; that Morison appropriates also the conclusion of the passage, which has a personal reference, "Conatus sum id præstare in universa plantarum historia, ut si quid pro ingenii mei tenuitate in hujusmodi studio profecerim, ad communem utilitatem proferrem." That Morison, thus, at so long an interval after the publication of the work of Cæsalpinus, borrowed from him without acknowledgement, and adopted his system so as to mutilate it, proves that he had neither the temper nor the talent of a discoverer; and justifies us withholding from him the credit which belongs to those, who, in his time, resumed the great undertaking of constructing a vegetable system.

[Note 70\16: Cuv. Leçons, &c. p. 486.]

[Note 71\16: Pref. p. i.]

[Note 72\16: Ib. p. ii.]

Among those whose efforts in this way had the greatest and earliest {384} influence, was undoubtedly our countryman, John Ray, who was Fellow of Trinity College, Cambridge, at the same time with Isaac Newton. But though Cuvier states[73\16] that Ray was the model of the systematists during the whole of the eighteenth century, the Germans claim a part of his merit for one of their countrymen, Joachim Jung, of Lubeck, professor at Hamburg.[74\16] Concerning the principles of this botanist, little was known during his life. But a manuscript of his book was communicated[75\16] to Ray in 1660, and from this time forwards, says Sprengel, there might be noticed in the writings of Englishmen, those better and clearer views to which Jung's principles gave birth. Five years after the death of Jung, his Doxoscopia Physica was published, in 1662; and in 1678, his Isagoge Phytoscopica. But neither of these works was ever much read; and even Linnæus, whom few things escaped which concerned botany, had, in 1771, seen none of Jung's works.

[Note 73\16: Leçons Hist. Sc. p. 487.]

[Note 74\16: Sprengel, ii. 27.]

[Note 75\16: Ray acknowledges this in his _Index Plant. Agri Cantab._ p. 87, and quotes from it the definition of caulis.]

I here pass over Jung's improvements of botanical language, and speak only of those which he is asserted to have suggested in the arrangement of plants. He examines, says Sprengel,[76\16] the value of characters of species, which, he holds, must not be taken from the thorns, nor from color, taste, smell, medicinal effects, time and place of blossoming. He shows, in numerous examples, what plants must be separated, though called by a common name, and what most be united, though their names are several.

[Note 76\16: Sprengel, ii. 29.]

I do not see in this much that interferes with the originality of Ray's method,[77\16] of which, in consequence of the importance ascribed to it by Cuvier, as we have already seen, I shall give an account, following that great naturalist.[78\16] I confine myself to the ordinary plants, and omit the more obscure vegetables, as mushrooms, mosses, ferns, and the like.

[Note 77\16: Methodus Plantarum Nova, 1682. Historia Plantarum, 1686.]

[Note 78\16: Cuv. Leçons Hist. Sc. 488.]

Such plants are composite or simple. The composite flowers are those which contain many florets in the same calyx.[79\16] These are subdivided according as they are composed altogether of complete florets, {385} or of half florets, or of a centre of complete florets, surrounded by a circumference or ray of demi-florets. Such are the divisions of the corymbiferæ, or compositæ.

[Note 79\16: Involucrum, in modern terminology.]

In the simple flowers, the seeds are naked, or in a pericarp. Those with naked seeds are arranged according to the number of the seeds, which may be one, two, three, four, or more. If there is only one, no subdivision is requisite: if there are two, Ray makes a subdivision, according as the flower has five petals, or a continuous corolla. Here we come to several natural families. Thus, the flowers with two seeds and five petals are the Umbelliferous plants; the monopetalous flowers with two seeds are the Stellatæ. He founds the division of four-seeded flowers on the circumstance of the leaves being opposite, or alternate; and thus again, we have the natural families of Asperifoliæ, as Echium, &c., which have the leaves alternate, and the Verticillatæ, as Salvia, in which the leaves are opposite. When the flower has more than four seeds, he makes no subdivision.

So much for simple flowers with naked seeds. In those where the seeds are surrounded by a pericarp, or fruit, this fruit is large, soft, and fleshy, and the plants are pomiferous; or it is small and juicy, and the fruit is a berry, as a Gooseberry.

If the fruit is not juicy, but dry, it is multiple or simple. If it be simple, we have the leguminose plants. If it be multiple, the form of the flower is to be attended to. The flower may be monopetalous, or tetrapetalous, or pentapetalous, or with still more divisions. The monopetalous may be regular or irregular; so may the tetrapetalous. The regular tetrapetalous flowers are, for example, the Cruciferæ, as Stock and Cauliflower; the irregular, are the papilionaceous plants, Peas, Beans, and Vetches; and thus we again come to natural families. The remaining plants are divided in the same way, into those with imperfect, and those with perfect, flowers. Those with imperfect flowers are the Grasses, the Rushes (Junci), and the like; among those with perfect flowers, are the Palmaceæ, and the Liliaceæ.

We see that the division of plants is complete as a system; all flowers must belong to one or other of the divisions. Fully to explain the characters and further subdivisions of these families, would be to write a treatise on botany; but it is easily seen that they exhaust the subject as far as they go.

Thus Ray constructed his system partly on the fruit and partly on the flower; or more properly, according to the expression of Linnæus, {386} comparing his earlier with his later system, he began by being a fructicist, and ended by being a corollist.[80\16]

[Note 80\16: Ray was a most industrious herbalizer, and I cannot understand on what ground Mirbel asserts (Physiol. Veg., tom. ii. p. 531,) that he was better acquainted with books than with plants.]

As we have said, a number of systems of arrangement of plants were published about this time, some founded on the fruit, some on the corolla, some on the calyx, and these employed in various ways. Rivinus[81\16] (whose real name was Bachman,) classified by the flower alone; instead of combining it with the fruit, as Ray had done.[82\16] He had the further merit of being the first who rejected the old division, of woody and herbaceous plants; a division which, though at variance with any system founded upon the structure of the plants was employed even by Tournefort, and only finally expelled by Linnæus.

[Note 81\16: Cuv. Leçons, 491.]

[Note 82\16: Historia Generalis ad rem Herbariam, 1690.]

It would throw little light upon the history of botany, especially for our purpose, to dwell on the peculiarities of these transitory systems. Linnæus,[83\16] after his manner, has given a classification of them. Rivinus, as we have just seen, was a corollist, according to the regularity and number of the petals; Hermann was a fructicist. Christopher Knaut[84\16] adopted the system of Ray, but inverted the order of its parts; Christian Knaut did nearly the same with regard to that of Rivinus, taking number before regularity in the flower.[85\16]

[Note 83\16: Philos. Bot. p. 21.]

[Note 84\16: Enumeratio Plantarum, &c., 1687.]

[Note 85\16: Linn.]

Of the systems which prevailed previous to that of Linnæus, Tournefort's was by far the most generally accepted. Joseph Pitton de Tournefort was of a noble family in Provence, and was appointed professor at the Jardin du Roi in 1683. His well-known travels in the Levant are interesting on other subjects, as well as botany. His Institutio Rei Herbariæ, published in 1700, contains his method, which is that of a corollist. He is guided by the regularity or irregularity of the flowers, by their form, and by the situation of the receptacle of the seeds below the calyx, or within it. Thus his classes are--those in which the flowers are campaniform, or bell-shaped; those in which they are infundibuliform, or funnel-shaped, as Tobacco; then the irregular flowers, as the Personatæ, which resemble an ancient mask; the Labiatæ, with their two lips; the Cruciform; the Rosaceæ, with flowers like a rose; the Umbelliferæ; the Caryophylleæ, as the {387} Pink; the Liliaceæ, with six petals, as the Tulip, Narcissus, Hyacinth, Lily; the Papilionaceæ, which are leguminous plants, the flower of which resembles a butterfly, as Peas and Beans; and finally, the Anomalous, as Violet, Nasturtium, and others.

Though this system was found to be attractive, as depending, in an evident way, on the most conspicuous part of the plant, the flower, it is easy to see that it was much less definite than systems like that of Rivinus, Hermann, and Ray, which were governed by number. But Tournefort succeeded in giving to the characters of genera a degree of rigor never before attained, and abstracted them in a separate form. We have already seen that the reception of botanical Systems has depended much on their arrangement into Genera.

Tournefort's success was also much promoted by the author inserting in his work a figure of a flower and fruit belonging to each genus; and the figures, drawn by Aubriet, were of great merit. The study of botany was thus rendered easy, for it could be learned by turning over the leaves of a book. In spite of various defects, these advantages gave this writer an ascendancy which lasted, from 1700, when his book appeared, for more than half a century. For though Linnæus began to publish in 1735, his method and his nomenclature were not generally adopted till 1760.

IV. THE REFORM OF LINNÆUS

Sect. 1.--Introduction of the Reform.

ALTHOUGH, perhaps, no man of science ever exercised a greater sway than Linnæus, or had more enthusiastic admirers, the most intelligent botanists always speak of him, not as a great discoverer, but as a judicious and strenuous Reformer. Indeed, in his own lists of botanical writers, he places himself among the "Reformatores;" and it is apparent that this is the nature of his real claim to admiration; for the doctrine of the sexes of plants, even if he had been the first to establish it, was a point of botanical physiology, a province of the {388} science which no one would select as the peculiar field of Linnæus's glory; and the formation of a system of arrangement on the basis of this doctrine, though attended with many advantages, was not an improvement of any higher order than those introduced by Ray and Tournefort. But as a Reformer of the state of Natural History in his time, Linnæus was admirable for his skill, and unparalleled in his success. And we have already seen, in the instance of the reform of mineralogy, as attempted by Mohs and Berzelius, that men of great talents and knowledge may fail in such an undertaking.

It is, however, only by means of the knowledge which he displays, and of the beauty and convenience of the improvements which he proposes, that any one can acquire such an influence as to procure his suggestions to be adopted. And even if original circumstances of birth or position could invest any one with peculiar prerogatives and powers in the republic of science, Karl Linné began his career with no such advantages. His father was a poor curate in Smaland, a province of Sweden; his boyhood was spent in poverty and privation; it was with great difficulty that, at the age of twenty-one, he contrived to subsist at the University of Upsal, whither a strong passion for natural history had urged him. Here, however, he was so far fortunate, that Olaus Rudbeck, the professor of botany, committed to him the care of the Botanic Garden.[86\16] The perusal of the works of Vaillant and Patrick Blair suggested to him the idea of an arrangement of plants, formed upon the sexual organs, the stamens and pistils; and of such an arrangement he published a sketch in 1731, at the age of twenty-four.

[Note 86\16: Sprengel, ii. 232.]

But we must go forwards a few years in his life, to come to the period to which his most important works belong. University and family quarrels induced him to travel; and, after various changes of scene, he was settled in Holland, as the curator of the splendid botanical garden of George Clifford, an opulent banker. Here it was[87\16] that he laid the foundation of his future greatness. In the two years of his residence at Harlecamp, he published nine works. The first, the Systema Naturæ, which contained a comprehensive sketch of the whole domain of Natural History, excited general astonishment, by the acuteness of the observations, the happy talent of combination, and the clearness of the systematic views. Such a work could not fail to procure considerable respect for its author. His Hortus Cliffortiana {389} and Musa Cliffortiana added to this impression. The weight which he had thus acquired, he proceeded to use for the improvement of botany. His Fundamenta Botanica and Bibliotheca Botanica appeared in 1736; his Critica Botanica and Genera Plantarum in 1737; his Classes Plantarum in 1738; his Species Plantarum was not published till 1753; and all these works appeared in many successive editions, materially modified.

[Note 87\16: Ibid. 234.]

This circulation of his works showed that his labors were producing their effect. His reputation grew; and he was soon enabled to exert a personal, as well as a literary, influence, on students of natural history. He became Botanist Royal, President of the Academy of Sciences at Stockholm, and Professor in the University of Upsal; and this office he held for thirty-six years with unrivalled credit; exercising, by means of his lectures, his constant publications, and his conversation, an extraordinary power over a multitude of zealous naturalists, belonging to every part of the world.

In order to understand more clearly the nature and effect of the reforms introduced by Linnæus into botany, I shall consider them under the four following heads;--Terminology, Nomenclature, Artificial System, and Natural System.

Sect. 2.--Linnæan Reform of Botanical Terminology.

IT must be recollected that I designate as Terminology, the system of terms employed in the description of objects of natural history; while by Nomenclature, I mean the collection of the names of species. The reform of the descriptive part of botany was one of the tasks first attempted by Linnæus; and his terminology was the instrument by which his other improvements were effected.

Though most readers, probably, entertain, at first, a persuasion that a writer ought to content himself with the use of common words in their common sense, and feel a repugnance to technical terms and arbitrary rules of phraseology, as pedantic and troublesome; it is soon found, by the student of any branch of science that, without technical terms and fixed rules, there can be no certain or progressive knowledge. The loose and infantine grasp of common language cannot hold objects steadily enough for scientific examination, or lift them from one stage of generalization to another. They must be secured by the rigid mechanism of a scientific phraseology. This necessity had been felt in all the sciences, from the earliest periods of their progress. But the {390} conviction had never been acted upon so as to produce a distinct and adequate descriptive botanical language. Jung, indeed,[88\16] had already attempted to give rules and precepts which should answer this purpose; but it was not till the Fundamenta Botanica appeared, that the science could be said to possess a fixed and complete terminology.

[Note 88\16: Isagoge Phytoscopica, 1679.]

To give an account of such a terminology, is, in fact, to give a description of a dictionary and grammar, and is therefore what cannot here be done in detail. Linnæus's work contains about a thousand terms of which the meaning and application are distinctly explained; and rules are given, by which, in the use of such terms, the botanist may avoid all obscurity, ambiguity, unnecessary prolixity and complexity, and even inelegance and barbarism. Of course the greater part of the words which Linnæus thus recognized had previously existed in botanical writers; and many of them had been defined with technical precision. Thus Jung[89\16] had already explained what was a composite, what a pinnate leaf; what kind of a bunch of flowers is a spike, a panicle, an umbel, a corymb, respectively. Linnæus extended such distinctions, retaining complete clearness in their separation. Thus, with him, composite leaves are further distinguished as digitate, pinnate, bipinnate, pedate, and so on; pinnate leaves are abruptly so, or with an odd one, or with a tendril; they are pinnate oppositely, alternately, interruptedly, articulately, decursively. Again, the inflorescence, as the mode of assemblage of the flowers is called, may be a tuft (fasciculus), a head (capitulum), a cluster (racemus), a bunch (thyrsus), a panicle, a spike, a catkin (amentum), a corymb, an umbel, a cyme, a whorl (verticillus). And the rules which he gives, though often apparently arbitrary and needless, are found, in practice, to be of great service by their fixity and connexion. By the good fortune of having had a teacher with so much delicacy of taste as Linnæus, in a situation of so much influence, Botany possesses a descriptive language which will long stand as a model for all other subjects.

[Note 89\16: Sprengel, ii. 28.]

It may, perhaps, appear to some persons, that such a terminology as we have here described must be enormously cumbrous; and that, since the terms are arbitrarily invested with their meaning, the invention of them requires no knowledge of nature. With respect to the former doubt, we may observe, that technical description is, in reality, the only description which is clearly intelligible; but that technical language cannot be understood without being learnt as any other {391} language is learnt; that is, the reader must connect the terms immediately with his own sensations and notions, and not mediately, through a verbal explanation; he must not have to guess their meaning, or to discover it by a separate act of interpretation into more familiar language as often as they occur. The language of botany must be the botanist's most familiar tongue. When the student has thus learnt to think in botanical language, it is no idle distinction to tell him that a bunch of grapes is not a cluster; that is, a thyrsus not a raceme. And the terminology of botany is then felt to be a useful implement, not an oppressive burden. It is only the schoolboy that complains of the irksomeness of his grammar and vocabulary. The accomplished student possesses them without effort or inconvenience.

As to the other question, whether the construction of such a botanical grammar and vocabulary implies an extensive and accurate acquaintance with the facts of nature, no one can doubt who is familiar with any descriptive science. It is true, that a person might construct an arbitrary scheme of distinctions and appellations, with no attention to natural objects; and this is what shallow and self-confident persons often set about doing, in some branch of knowledge with which they are imperfectly acquainted. But the slightest attempt to use such a phraseology leads to confusion; and any continued use of it leads to its demolition. Like a garment which does not fit us, if we attempt to work in it we tear it in pieces.

The formation of a good descriptive language is, in fact, an inductive process of the same kind as those which we have already noticed in the progress of natural history. It requires the discovery of fixed characters, which discovery is to be marked and fixed, like other inductive steps, by appropriate technical terms. The characters must be so far fixed, that the things which they connect must have a more permanent and real association than the things which they leave unconnected. If one bunch of grapes were really a racemus, and another a thyrsus, according to the definition of these terms, this part of the Linnæan language would lose its value; because it would no longer enable us to assert a general proposition with respect to one kind of plants.

Sect. 3.--Linnæan Reform of Botanical Nomenclature.

IN the ancient writers each recognized kind of plants had a distinct name. The establishment of Genera led to the practice of designating {392} Species by the name of the genus, with the addition of a "phrase" to distinguish the species. These phrases, (expressed in Latin in the ablative case,) were such as not only to mark, but to describe the species, and were intended to contain such features of the plant as were sufficient to distinguish it from others of the same genus. But in this way the designation of a plant often became a long and inconvenient assemblage of words. Thus different kinds of Rose were described as, Rosa campestris, spinis carens, biflora (Rosa alpina.) Rosa aculeata, foliis odoratis subtus rubiginosis (R. eglanteria.) Rosa carolina fragrans, foliis medio tenus serratis (R. carolina.) Rosa sylvestris vulgaris, flore odorato incarnato (R. canina.) And several others. The prolixity of these appellations, their variety in every different author, the insufficiency and confusion of the distinctions which they contained, were felt as extreme inconveniences. The attempt of Bauhin to remedy this evil by a Synonymy, had, as we have seen, failed at the time, for want of any directing principle; and was become still more defective by the lapse of years and the accumulation of fresh knowledge and new books. Haller had proposed to distinguish the species of each genus by the numbers 1, 2, 3, and so on; but botanists found that their memory could not deal with such arbitrary abstractions. The need of some better nomenclature was severely felt.

The remedy which Linnæus finally introduced was the use of trivial names; that is, the designation of each species by the name of the genus along with a single conventional word, imposed without any general rule. Such names are added above in parentheses, to the specimens of the names previously in use. But though this remedy was found to be complete and satisfactory, and is now universally adopted in every branch of natural history, it was not one of the reforms which Linnæus at first proposed. Perhaps he did not at first see its full value; or, if he did, we may suppose that it required more self-confidence than he possessed, to set himself to introduce and establish ten thousand new names in the botanical world. Accordingly, the first attempts of Linnæus at the improvement of the nomenclature of botany were, the proposal of fixed and careful rules for the generic name, and for the descriptive phrase. Thus, in his Critica Botanica, he gives many precepts concerning the selection of the names of {393} genera, intended to secure convenience or elegance. For instance, that they are to be single words;[90\16] he substitutes atropa for bella donna, and leontodon for dens leonis; that they are not to depend upon the name of another genus,[91\16] as acriviola, agrimonoides; that they are not[92\16] to be "sesquipedalia;" and, says he, any word is sesquipedalian to me, which has more than twelve letters, as kalophyllodendron, for which he substitutes calophyllon. Though some of these rules may seem pedantic, there is no doubt that, taken altogether, they tend exceedingly, like the labors of purists in other languages, to exclude extravagance, caprice, and barbarism in botanical speech.

[Note 90\16: Phil. Bot. 224.]

[Note 91\16: Ib. 228, 229.]

[Note 92\16: Ib. 252.]

The precepts which he gives for the matter of the "descriptive phrase," or, as it is termed in the language of the Aristotelian logicians, the "differentia," are, for the most part, results of the general rule, that the most fixed characters which can be found are to be used; this rule being interpreted according to all the knowledge of plants which had then been acquired. The language of the rules was, of course, to be regulated by the terminology, of which we have already spoken.

Thus, in the Critica Botanica, the name of a plant is considered as consisting of a generic word and a specific phrase; and these are, he says,[93\16] the right and left hands of the plant. But he then speaks of another kind of name; the trivial name, which is opposed to the scientific. Such names were, he says,[94\16] those of his predecessors, and especially of the most ancient of them. Hitherto[95\16] no rules had been given for their use. He manifestly, at this period, has small regard for them. "Yet," he says, "trivial names may, perhaps, be used on this account,--that the differentia often turns out too long to be convenient in common use, and may require change as new species are discovered. However," he continues, "in this work we set such names aside altogether, and attend only to the differentiæ."

[Note 93\16: Ib. 266.]

[Note 94\16: Ib. 261.]

[Note 95\16: Ib. 260.]

Even in the Species Plantarum, the work which gave general currency to these trivial names, he does not seem to have yet dared to propose so great a novelty. They only stand in the margin of the work. "I have placed them there," he says in his Preface, "that, without circumlocution, we may call every herb by a single name; I have done this without selection, which would require more time. And I beseech all sane botanists to avoid most religiously ever {394} proposing a trivial name without a sufficient specific distinction, lest the science should fall into its former barbarism."

It cannot be doubted, that the general reception of these trivial names of Linnæus, as the current language among botanists, was due, in a very great degree, to the knowledge, care, and skill with which his characters, both of genera and of species, were constructed. The rigorous rules of selection and expression which are proposed in the Fundamenta Botanica and Critica Botanica, he himself conformed to; and this scrupulosity was employed upon the results of immense labor. "In order that I might make myself acquainted with the species of plants," he says, in the preface to his work upon them, "I have explored the Alps of Lapland, the whole of Sweden, a part of Norway, Denmark, Germany, Belgium, England, France: I have examined the Botanical Gardens of Paris, Oxford, Chelsea, Harlecamp, Leyden, Utrecht, Amsterdam, Upsal, and others: I have turned over the Herbals of Burser, Hermann, Clifford, Burmann, Oldenland, Gronovius, Royer, Sloane, Sherard, Bobart, Miller, Tournefort, Vaillant, Jussieu, **Surian, Beck, Brown, &c.: my dear disciples have gone to distant lands, and sent me plants from thence; Kerlen to Canada, Hasselquist to Egypt, Asbech to China, Toren to Surat, Solander to England, Alstrœmer to Southern Europe, Martin to Spitzbergen, Pontin to Malabar, Kœhler to Italy, Forskähl to the East, Lœfling to Spain, Montin to Lapland: my botanical friends have sent me many seeds and dried plants from various countries: Lagerström many from the East Indies; Gronovius most of the Virginian; Gmelin all the Siberian; Burmann those of the Cape." And in consistency with this habit of immense collection of materials, is his maxim,[96\16] that "a person is a better botanist in proportion as he knows more species." It will easily be seen that this maxim, like Newton's declaration that discovery requires patient thought alone, refers only to the exertions of which the man of genius is conscious; and leaves out of sight his peculiar endowments, which he does not see because they are part of his power of vision. With the taste for symmetry which dictated the Critica Botanica, and the talent for classification which appears in the Genera Plantarum, and the Systema Naturæ, a person must undoubtedly rise to higher steps of classificatory knowledge and skill, as he became acquainted with a greater number of facts.

[Note 96\16: Phil. Bot. 259.]

The acknowledged superiority of Linnæus in the knowledge of the {395} matter of his science, induced other persons to defer to him in what concerned its form; especially when his precepts were, for the most part, recommended strongly both by convenience and elegance. The trivial names of the Species Plantarum were generally received; and though some of the details may have been altered, the immense advantage of the scheme ensures its permanence.

Sect. 4.--Linnæus's Artificial System.

WE have already seen, that, from the time of Cæsalpinus, botanists had been endeavoring to frame a systematic arrangement of plants. All such arrangements were necessarily both artificial and natural: they were artificial, inasmuch as they depended upon assumed principles, the number, form, and position of certain parts, by the application of which the whole vegetable kingdom was imperatively subdivided; they were natural, inasmuch as the justification of this division was, that it brought together those plants which were naturally related. No system of arrangement, for instance, would have been tolerated which, in a great proportion of cases, separated into distant parts of the plan the different species of the same genus. As far as the main body of the genera, at least, all systems are natural.

But beginning from this line, we may construct our systems with two opposite purposes, according as we endeavor to carry our assumed principle of division rigorously and consistently through the system, or as we wish to associate natural families of a wider kind than genera. The former propensity leads to an artificial, the latter to a natural method. Each is a System of Plants; but in the first, the emphasis is thrown on the former word of the title, in the other, on the latter.

The strongest recommendation of an artificial system, (besides its approaching to a natural method,) is, that it shall be capable of easy use; for which purpose, the facts on which it depends must be apparent in their relations, and universal in their occurrence. The system of Linnæus, founded upon the number, position, and other circumstances of the stamina and pistils, the reproductive organs of the plants, possessed this merit in an eminent degree, as far as these characters are concerned; that is, as far as the classes and orders. In its further subdivision into genera, its superiority was mainly due to the exact observation and description, which we have already had to notice as talents which Linnæus peculiarly possessed.

The Linnæan system of plants was more definite than that of {396} Tournefort, which was governed by the corolla; for number is more definite than irregular form. It was more readily employed than any of those which depend on the fruit, for the flower is a more obvious object, and more easily examined. Still, it can hardly be doubted, that the circumstance which gave the main currency to the system of Linnæus was its physiological signification: it was the Sexual System. The relation of the parts to which it directed the attention, interested both the philosophical faculty and the imagination. And when, soon after the system had become familiar in our own country, the poet of The Botanic Garden peopled the bell of every flower with "Nymphs" and "Swains," his imagery was felt to be by no means forced and far-fetched.

The history of the doctrine of the sexes of plants, as a point of physiology, does not belong to this place; and the Linnæan system of classification need not be longer dwelt upon for our present purpose. I will only explain a little further what has been said, that it is, up to a certain point, a natural system. Several of Linnæus's classes are, in a great measure, natural associations, kept together in violation of his own artificial rules. Thus the class Diadelphia, in which, by the system, the filaments of the stamina should be bound together in two parcels, does, in fact, contain many genera which are_ monadelphous_, the filaments of the stamina all cohering so as to form one bundle only; as in Genista, Spartium, Anthyllis, Lupinus, &c. And why is this violation of rule? Precisely because these genera all belong to the natural tribe of Papilionaceous plants, which the author of the system could not prevail upon himself to tear asunder. Yet in other cases Linnæus was true to his system, to the injury of natural alliances, as he was, for instance, in another portion of this very tribe of Papilionaceæ; for there are plants which undoubtedly belong to the tribe, but which have ten separate stamens; and these he placed in the order Decandria. Upon the whole, however, he inclines rather to admit transgression of art than of nature.

The reason of this inclination was, that he rightly considered an artificial method as instrumental to the investigation of a natural one; and to this part of his views we now proceed.

Sect. 5.--Linnæus's Views on a Natural Method.

THE admirers of Linnæus, the English especially, were for some time in the habit of putting his Sexual System in opposition to the Natural Method, which about the same time was attempted in France. And {397} as they often appear to have imagined that the ultimate object of botanical methods was to know the name of plants, they naturally preferred the Swedish method, which is excellent as a finder. No person, however, who wishes to know botany as a science, that is, as a body of general truths, can be content with making names his ultimate object. Such a person will be constantly and irresistibly led on to attempt to catch sight of the natural arrangement of plants, even before he discovers, as he will discover by pursuing such a course of study, that the knowledge of the natural arrangement is the knowledge of the essential construction and vital mechanism of plants. He will consider an artificial method as a means of arriving at a natural method. Accordingly, however much some of his followers may have overlooked this, it is what Linnæus himself always held and taught. And though what he executed with regard to this object was but little,[97\16] the distinct manner in which he presented the relations of an artificial and natural method, may justly be looked upon as one of the great improvements which he introduced into the study of his science.

[Note 97\16: The natural orders which he proposed are a bare enumeration of genera, and have not been generally followed.]

Thus in the Classes Plantarum (1747), he speaks of the difficulty of the task of discovering the natural orders, and of the attempts made by others. "Yet," he adds, "I too have labored at this, have done something, have much still to do, and shall labor at the object as long as I live." He afterwards proposed sixty-seven orders, as the fragments of a natural method, always professing their imperfection.[98\16] And in others of his works[99\16] he lays down some antitheses on the subject after his manner. "The natural orders teach us the nature of plants; the artificial orders enable us to recognize plants. The natural orders, without a key, do not constitute a Method; the Method ought to be available without a master."

[Note 98\16: Phil. Bot. p. 80.]

[Note 99\16: Genera Plantarum, 1764. See Prælect. in Ord. Nat. p. xlviii.]

That extreme difficulty must attend the formation of a Natural Method, may be seen from the very indefinite nature of the Aphorisms upon this subject which Linnæus has delivered, and which the best botanists of succeeding times have assented to. Such are these;--the Natural Orders must be formed by attention, not to one or two, but to all the parts of plants;--the same organs are of great importance in regulating the divisions of one part of the system, and {398} of small importance in another part;[100\16]--the Character does not constitute the Genus, but the Genus the Character;--the Character is necessary, not to make the Genus, but to recognize it. The vagueness of these maxims is easily seen; the rule of attending to all the parts, implies, that we are to estimate their relative importance, either by physiological considerations (and these again lead to arbitrary rules, as, for instance, the superiority of the function of nutrition to that of reproduction), or by a sort of latent naturalist instinct, which Linnæus in some passages seems to recognize. "The Habit of a plant," he says,[101\16] "must be secretly consulted. A practised botanist will distinguish, at the first glance, the plants of different quarters of the globe, and yet will be at a loss to tell by what mark he detects them. There is, I know not what look,--sinister, dry, obscure in African plants; superb and elevated, in the Asiatic; smooth and cheerful, in the American; stunted and indurated, in the Alpine."

[Note 100\16: Phil. Bot. p. 172.]

[Note 101\16: Ib. p. 171.]

Again, the rule that the same parts are of very different value in different Orders, not only leaves us in want of rules or reasons which may enable us to compare the marks of different Orders, but destroys the systematic completeness of the natural arrangement. If some of the Orders be regulated by the flower and others by the fruit, we may have plants, of which the flower would place them in one Order, and the fruit in another. The answer to this difficulty is the maxim already stated;--that no Character makes the Order; and that if a Character do not enable us to recognize the Order, it does not answer its purpose, and ought to be changed for another.

This doctrine, that the Character is to be employed as a servant and not as a master, was a stumbling-block in the way of those disciples who looked only for dogmatical and universal rules. One of Linnæus's pupils, Paul Dietrich Giseke, has given us a very lively account of his own perplexity on having this view propounded to him, and of the way in which he struggled with it. He had complained of the want of intelligible grounds, in the collection of natural orders given by Linnæus. Linnæus[102\16] wrote in answer, "You ask me for the characters of the Natural Orders: I confess I cannot give them." Such a reply naturally increased Giseke's difficulties. But afterwards, in 1771, he had the good fortune to spend some time at Upsal; and he narrates a conversation which he held with the great {399} teacher on this subject, and which I think may serve to show the nature of the difficulty;--one by no means easily removed, and by the general reader, not even readily comprehended with distinctness. Giseke began by conceiving that an Order must have that attribute from which its name is derived;--that the Umbellatæ must have their flower disposed in an umbel. The "mighty master" smiled,[103\16] and told him not to look at names, but at nature. "But" (said the pupil) "what is the use of the name, if it does not mean what it professes to mean?" "It is of small import" (replied Linnæus) "what you call the Order, if you take a proper series of plants and give it some name, which is clearly understood to apply to the plants which you have associated. In such cases as you refer to, I followed the logical rule, of borrowing a name a potiori, from the principal member. Can you" (he added) "give me the character of any single Order?" Giseke. "Surely, the character of the Umbellatæ is, that they have an umbel?" Linnæus. "Good; but there are plants which have an umbel, and are not of the Umbellatæ." G. "I remember. We must therefore add, that they have two naked seeds." L. "Then, Echinophora, which has only one seed, and Eryngium, which has not an umbel, will not be Umbellatæ; and yet they are of the Order." G. "I would place Eryngium among the Aggregatæ. L. "No; both are beyond dispute Umbellatæ. Eryngium has an involucrum, five stamina, two pistils, &c. Try again for your Character." G. "I would transfer such plants to the end of the Order, and make them form the transition to the next Order. Eryngium would connect the Umbellatæ with the Aggregatæ." L. "Ah! my good friend, the Transition from Order to Order is one thing; the Character of an Order is another. The Transitions I could indicate; but a Character of a Natural Order is impossible. I will not give my reasons for the distribution of Natural Orders which I have published. You or some other person, after twenty or after fifty years, will discover them, and see I was in the right."

[Note 102\16: Linnæi Prælectiones, Pref. p. xv.]

[Note 103\16: "Subrisit ὁ πανυ."]

I have given a portion of this curious conversation in order to show that the attempt to establish Natural Orders leads to convictions which are out of the domain of the systematic grounds on which they profess to proceed. I believe the real state of the case to be that the systematist, in such instances, is guided by an unformed and undeveloped apprehension of physiological functions. The ideas of the form, {400} number, and figure of parts are, in some measure, overshadowed and superseded by the rising perception of organic and vital relations; and the philosopher who aims at a Natural Method, while he is endeavoring merely to explore the apartment in which he had placed himself, that of Arrangement, is led beyond it, to a point where another light begins, though dimly, to be seen; he is brought within the influence of the ideas of Organization and Life.

The sciences which depend on these ideas will be the subject of our consideration hereafter. But what has been said may perhaps serve to explain the acknowledged and inevitable imperfection of the unphysiological Linnæan attempts towards a natural method. "Artificial Glasses are," Linnæus says, "a substitute for Natural, till Natural are detected." But we have not yet a Natural Method. "Nor," he says, in the conversation above cited, "can we have a Natural Method; for a Natural Method implies Natural Classes and Orders; and these Orders must have Characters." "And they," he adds in another place,[104\16] "who, though they cannot obtain a complete Natural Method, arrange plants according to the fragments of such a method, to the rejection of the Artificial, seem to me like persons who pull down a convenient vaulted room, and set about building another, though they cannot turn the vault which is to cover it."

[Note 104\16: Gen. Plant. in Prælect. p. xii.]

How far these considerations deterred other persons from turning their main attention to a natural method, we shall shortly see; but in the mean time, we must complete the history of the Linnæan Reform.

Sect. 6.--Reception and Diffusion of the Linnæan Reform.

WE have already seen that Linnæus received, from his own country, honors and emoluments which mark his reputation as established, as early as 1740; and by his publications, his lectures, and his personal communications, he soon drew round him many disciples, whom he impressed strongly with his own doctrines and methods. It would seem that the sciences of classification tend, at least in modern times more than other sciences, to collect about the chair of the teacher a large body of zealous and obedient pupils; Linnæus and Werner were by far the most powerful heads of schools of any men who appeared in the course of the last century. Perhaps one reason of this is, that in these sciences, consisting of such an enormous multitude of species, of descriptive {401} particulars, and of previous classifications, the learner is dependent upon the teacher more completely, and for a longer time than in other subjects of speculation: he cannot so soon or so easily cast off the aid and influence of the master, to pursue reasonings and hypotheses of his own. Whatever the cause may be, the fact is, that the reputation and authority of Linnæus, in the latter part of his life, were immense. He enjoyed also royal favor, for the King and Queen of Sweden were both fond of natural history. In 1753, Linnæus received from the hand of his sovereign the knighthood of the Polar Star, an honor which had never before been conferred for literary merit; and in 1756, was raised to the rank of Swedish nobility by the title of Von Linné; and this distinction was confirmed by the Diet in 1762. He lived, honored and courted, to the age of seventy-one; and in 1778 was buried in the cathedral of Upsal, with many testimonials of public respect and veneration.

De Candolle[105\16] assigns, as the causes of the successes of the Linnæan system,--the specific names,--the characteristic phrase,--the fixation of descriptive language,--the distinction of varieties and species,--the extension of the method to all the kingdoms of nature,--and the practice of introducing into it the species most recently discovered. This last course Linnæus constantly pursued; thus making his works the most valuable for matter, as they were the most convenient in form. The general diffusion of his methods over Europe may be dated, perhaps, a few years after 1760, when the tenth and the succeeding editions of the Systema Naturæ were in circulation, professing to include every species of organized beings. But his pupils and correspondents effected no less than his books, in giving currency to his system. In Germany,[106\16] it was defended by Ludwig, Gesner, Fabricius. But Haller, whose reputation in physiology was as great as that of Linnæus in methodology, rejected it as too merely artificial. In France, it did not make any rapid or extensive progress: the best French botanists were at this time occupied with the solution of the great problem of the construction of a Natural Method. And though the rhetorician Rousseau charmed, we may suppose, with the elegant precision of the Philosophia Botanica, declared it to be the most philosophical work he had ever read in his life, Buffon and Andanson, describers and philosophers of a more ambitious school, felt a repugnance to the rigorous rules, and limited, but finished, undertakings of the Swedish naturalist. To resist his {402} criticism and his influence, they armed themselves with dislike and contempt.

[Note 105\16: Théor. Elém. p. 40.]

[Note 106\16: Sprengel, ii. 244.]

In England the Linnæan system was very favorably received:--perhaps the more favorably, for being a strictly artificial system. For the indefinite and unfinished form which almost inevitably clings to a natural method, appears to be peculiarly distasteful to our countrymen. It might seem as if the suspense and craving which comes with knowledge confessedly incomplete were so disagreeable to them, that they were willing to avoid it, at any rate whatever; either by rejecting system altogether, or by accepting a dogmatical system without reserve. The former has been their course in recent times with regard to Mineralogy; the latter was their proceeding with respect to the Linnæan Botany. It is in this country alone, I believe, that Wernerian and Linnæan Societies have been instituted. Such appellations somewhat remind us of the Aristotelian and Platonic schools of ancient Greece. In the same spirit it was, that the Artificial System was at one time here considered, not as subsidiary and preparatory to the Natural Orders, but as opposed to them. This was much as if the disposition of an army in a review should be considered as inconsistent with another arrangement of it in a battle.

When Linnæus visited England in 1736, Sloane, then the patron of natural history in this country, is said to have given him a cool reception, such as was perhaps most natural from an old man to a young innovator; and Dillenius, the Professor at Oxford, did not accept the sexual system. But as Pulteney, the historian of English Botany, says, when his works became known, "the simplicity of the classical characters, the uniformity of the generic notes, all confined to the parts of the fructification, and the precision which marked the specific distinctions, merits so new, soon commanded the assent of the unprejudiced."

Perhaps the progress of the introduction of the Linnæan System into England will be best understood from the statement of T. Martyn, who was Professor of Botany in the University of Cambridge, from 1761 to 1825. "About the year 1750," he says,[107\16] "I was a pupil of the school of our great countryman Ray; but the rich vein of knowledge, the profoundness and precision, which I remarked everywhere in the Philosophia Botanica, (published in 1751,) withdrew me from my first master, and I became a decided convert to that system of botany which has since been generally received. In 1753, the Species {403} Plantarum, which first introduced the specific names, made me a Linnæan completely." In 1763, he introduced the system in his lectures at Cambridge, and these were the first Linnæan lectures in England. Stillingfleet had already, in 1757, and Lee, in 1760, called the attention of English readers to Linnæus. Sir J. Hill, (the king's gardener at Kew,) in his Flora Britannica, published in 1760, had employed the classes and generic characters, but not the nomenclature; but the latter was adopted by Hudson, in 1762, in the Flora Anglica.

[Note 107\16: Pref. to Language of Botany, 3rd edit. 1807.]

Two young Swedes, pupils of Linnæus, Dryander and Solander, settled in England, and were in intimate intercourse with the most active naturalists, especially with Sir Joseph Banks, of whom the former was librarian, and the latter a fellow-traveller in Cook's celebrated voyage. James Edward Smith was also one of the most zealous disciples of the Linnæan school; and, after the death of Linnæus, purchased his Herbariums and Collections. It is related,[108\16] as a curious proof of the high estimation in which Linnæus was held, that when the Swedish government heard of this bargain, they tried, though too late, to prevent these monuments of their countryman's labor and glory being carried from his native land, and even went so far as to send a frigate in pursuit of the ship which conveyed them to England. Smith had, however, the triumph of bringing them home in safety. On his death they were purchased by the Linnæan Society. Such relics serve, as will easily be imagined, not only to warm the reverence of his admirers, but to illustrate his writings: and since they have been in this country, they have been the object of the pilgrimage of many a botanist, from every part of Europe.

[Note 108\16: Trapp's Transl. of Stower's Life of Linnæus, p. 314.]

I have purposely confined myself to the history of the Linnæan system in the cases in which it is most easily applicable, omitting all consideration of more obscure and disputed kinds of vegetables, as ferns, mosses, fungi, lichens, sea-weeds, and the like. The nature and progress of a classificatory science, which it is our main purpose to bring into view, will best be understood by attending, in the first place, to the cases in which such a science has been pursued with the most decided success; and the advances which have been made in the knowledge of the more obscure vegetables, are, in fact, advances in artificial classification, only in as far as they are advances in natural classification, and in physiology.

To these subjects we now proceed. {404}

V. PROGRESS TOWARDS A NATURAL SYSTEM OF BOTANY

WE have already said, that the formation of a Natural System of classification must result from a comparison of all the resemblances and differences of the things classed; but that, in acting upon this maxim, the naturalist is necessarily either guided by an obscure and instinctive feeling, which is, in fact, an undeveloped recognition of physiological relations, or else acknowledges physiology for his guide, though he is obliged to assume arbitrary rules in order to interpret its indications. Thus all Natural Classification of organized beings, either begins or soon ends in Physiology; and can never advance far without the aid of that science. Still, the progress of the Natural Method in botany went to such a length before it was grounded entirely on the anatomy of plants, that it will be proper, and I hope instructive, to attempt a sketch of it here.

As I have already had occasion to remark, the earlier systems of plants were natural; and they only ceased to be so, when it appeared that the problem of constructing a system admitted of a very useful solution, while the problem of devising a natural system remained insoluble. But many botanists did not so easily renounce the highest object of their science. In France, especially, a succession of extraordinary men labored at it with no inconsiderable success: and they were seconded by worthy fellow-laborers in Germany and elsewhere.

The precept of taking into account all the parts of plants according to their importance, may be applied according to arbitrary rules. We may, for instance, assume that the fruit is the most important part; or we may make a long list of parts, and look for agreement in the greatest possible number of these, in order to construct our natural orders. The former course was followed by Gærtner;[109\16] the latter by Adanson. Gærtner's principles, deduced from the dissection of more than a thousand kinds of fruits,[110\16] exercised, in the sequel, a great and {405} permanent influence on the formation of natural classes. Adanson's attempt, bold and ingenious, belonged, both in time and character, to a somewhat earlier stage of the subject.[111\16] Enthusiastic and laborious beyond belief but self-confident, and contemptuous of the labors of others, Michael Adanson had collected, during five years spent in Senegal, an enormous mass of knowledge and materials; and had formed plans for the systems which he conceived himself thus empowered to reach, far beyond the strength and the lot of man.[112\16] In his Families of Plants, however, all agree that his labors were of real value to the science. The method which he followed is thus described by his eloquent and philosophical eulogist.[113\16]

[Note 109\16: De Fructibus et Seminibus Plantarum. Stuttg. 1788-1791.]

[Note 110\16: Sprengel, ii. 290.]

[Note 111\16: Familles des Plantes, 1763.]

[Note 112\16: Cuvier's Eloge.]

[Note 113\16: Cuv. Eloges, tom. i. p. 282.]

Considering each organ by itself, he formed, by pursuing its various modifications, a system of division, in which he arranged all known species according to that organ alone. Doing the same for another organ, and another, and so for many, he constructed a collection of systems of arrangement, each artificial,--each founded upon one assumed organ. The species which come together in all these systems are, of all, naturally the nearest to each other; those which are separated in a few of the systems, but contiguous in the greatest number, are naturally near to each other, though less near than the former; those which are separated in a greater number, are further removed from each other in nature; and they are the more removed, the fewer are the systems in which they are associated.

Thus, by this method, we obtain the means of estimating precisely the degree of natural affinity of all the species which our systems include, independent of a physiological knowledge of the influence of the organs. But the method has, Cuvier adds, the inconvenience of presupposing another kind of knowledge, which, though it belongs only to descriptive natural history, is no less difficult to obtain;--the knowledge, namely, of all species, and of all the organs of each. A single one neglected, may lead to relations the most false; and Adanson himself, in spite of the immense number of his observations, exemplifies this in some instances.

We may add, that in the division of the structure into organs, and in the estimation of the gradations of these in each artificial system, there is still room for arbitrary assumption.

In the mean time, the two Jussieus had presented to the world a "Natural Method," which produced a stronger impression than the {406} "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,[114\16] 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.

[Note 114\16: Mém. Ac. P. 1774.]

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.[115\16] But this appears, from a recent statement,[116\16] 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 Ranunculaceæ; and he was wont to relate (as his son informs us) that it {407} 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."

[Note 115\16: Prodromus Floræ Penins. Ind. Orient. Wight and Walker-Arnott, Introd. p. xxxv.]

[Note 116\16: By Adrien de Jussieu, son of Antoine Laurent, in the Annales des Sc. Nat., Nov. 1834.]

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 {408} 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[117\16] 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[118\16] 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.

[Note 117\16: Hist. Sc. Nat. ii. 197.]

[Note 118\16: Hist. Sc. Nat. i. pp. 196, 290.]

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,[119\16] 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. Roscoe[120\16] 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. {409}

[Note 119\16: Sprengel, ii. 296; and, there quoted, Flore Française, t. i. 3, 1778. Mém. Ac. P. 1785. Journ. Hist. Nat. t. i. For Lamarck's Méthode Analytique, see Dumeril, Sc. Nat. i. Art. 390.]

[Note 120\16: 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,[121\16] 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[122\16] 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 Floræ Novæ 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."

[Note 121\16: Linn. Tr. vol. xi. p. 50.]

[Note 122\16: Ibid. vol. viii.]

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.[123\16] Mr. Brown has also published {410} special disquisitions on parts of the Natural System; as on Jussieu's Proteaceæ;[124\16] on the Asclepiadeæ, a natural family of plants which must be separated from Jussieu's Apocyneæ;[125\16] and other similar labors.

[Note 123\16: Roberto Brown, Britanniarum gloriæ atque ornamento, totam Botanices scientiam ingenio mirifico complectenti. &c.]

[Note 124\16: Linn. Tr. vol. x. 1809.]

[Note 125\16: Mem. of Wernerian N. H. Soc. vol. i. 1809.]

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 Primæ Lineæ Systematis Naturæ (1834); Fries's Corpus Florarum provincialium Sueciæ (1835); Martins's Conspectus Regni Vegetablis 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 {411} (1843); Adrien de Jussieu's **Cours Elémentaire d'Histoire Naturelle. Botanique (1844).

Mr. Lindley, in this as in all his works, urges strongly the superior value of natural as compared with artificial systems; his principles being, I think, nearly such as I have attempted to establish in the Philosophy of the Sciences, Book viii., Chapter ii. He states that the leading idea which has been kept in view in the compilation of his work is this maxim of Fries: "Singula sphæra (sectio) ideam quandam exponit, indeque ejus character notione simplici optime exprimitur;" and he is hence led to think that the true characters of all natural assemblages are extremely simple.

One of the leading features in Mr. Lindley's system is that he has thrown the Natural Orders into groups subordinate to the higher divisions of Classes and Sub-classes. He had already attempted this, in imitation of Agardh and Bartling, in his Nixus Plantarum (1838). The groups of Natural Orders were there called Nixus (tendencies); and they were denoted by names ending in ales; but these groups were further subordinated to Cohorts. Thus the first member of the arrangement was Class 1. EXOGENÆ. Sub-class 1. POLYPETALÆ. Cohort 1. ALBUMINOSÆ. Nixus 1. Ranales. Natural Orders included in this Nixus, Ranunculaceæ, Saraceniceæ, Papaveraceæ, &c. In the Vegetable Kingdom, the groups of Natural Orders are termed Alliances. In this work, the Sub-classes of the EXOGENS are four: I. DICLINOUS; II. HYPOGYNOUS; III. PERIGYNOUS; IV. EPIGYNOUS; and the Alliances are subordinated to these without the intervention of Cohorts.

Mr. Lindley has also, in this as in other works, given English names for the Natural Orders. Thus for Nymphaceæ, Ranunculaceæ, Tamaricaceæ, Zygophyllaceæ, Eleatrinaceæ, he substitutes Water-Lilies, Crowfoots, Tamarisks, Bean-Capers, and Water-Peppers; for Malvaceæ, Aurantiaceæ, Gentianaceæ, Primulaceæ, Urtiaceæ, Euphorbiaceæ, he employs Mallow-worts, Citron-worts, Gentian-worts, Prim-worts, Nettle-worts, Spurge-worts; and the terms Orchids, Hippurids, Amaryllids, Irids, Typhads, Arads, Cucurbits, are taken as English equivalents for Orchidaceæ, Haloragaceæ, Amaryllidaceæ, Iridaceæ, Typhaceæ, Araceæ, Cucurbitaceæ. All persons who wish success to the study of botany in England must rejoice to see it tend to assume this idiomatic shape.] {412}

VI. THE PROGRESS OF SYSTEMATIC ZOOLOGY

THE history of Systematic Botany, as we have presented it, may be considered as a sufficient type of the general order of progression in the sciences of classification. It has appeared, in the survey which we have had to give, that this science, no less than those which we first considered, has been formed by a series of inductive processes, and has, in its history, Epochs at which, by such processes, decided advances were made. The important step in such cases is, the seizing upon some artificial mark which conforms to natural resemblances;--some basis of arrangement and nomenclature by means of which true propositions of considerable generality can be enunciated. The advance of other classificatory sciences, as well as botany, must consist of such steps; and their course, like that of botany, must (if we attend only to the real additions made to knowledge,) be gradual and progressive, from the earliest times to the present.

To exemplify this continued and constant progression in the whole range of Zoology, would require vast knowledge and great labor; and is, perhaps, the less necessary, after we have dwelt so long on the history of Botany, considered in the same point of view. But there are a few observations respecting Zoology in general which we are led to make in consequence of statements recently promulgated; for these statements seem to represent the history of Zoology as having followed a course very different from that which we have just ascribed to the classificatory sciences in general. It is held by some naturalists, that not only the formation of a systematic classification in Zoology dates as far back as Aristotle; but that his classification is, in many respects, superior to some of the most admired and recent attempts of modern times.

If this were really the case, it would show that at least the idea of a Systematic Classification had been formed and developed long previous to the period to which we have assigned such a step; and it would be difficult to reconcile such an early maturity of Zoology with the conviction, which we have had impressed upon us by the other {413} parts of our history, that not only labor but time, not only one man of genius but several, and those succeeding each other, are requisite to the formation of any considerable science.

But, in reality, the statements to which we refer, respecting the scientific character of Aristotle's Zoological system, are altogether without foundation; and this science confirms the lessons taught us by all the others. The misstatements respecting Aristotle's doctrines are on this account so important, and are so curious in themselves, that I must dwell upon them a little.

Aristotle's nine Books On Animals are a work enumerating the differences of animals in almost all conceivable respects;--in the organs of sense, of motion, of nutrition, the interior anatomy, the exterior covering, the manner of life, growth, generation, and many other circumstances. These differences are very philosophically estimated. "The corresponding parts of animals," he says,[126\16] "besides the differences of quality and circumstance, differ in being more or fewer, greater or smaller, and, speaking generally, in excess and defect. Thus some animals have crustaceous coverings, others hard shells; some have long beaks, some short; some have many wings, some have few; Some again have parts which others want, as crests and spurs." He then makes the following important remark: "Some animals have parts which correspond to those of others, not as being the same in species, nor by excess and defect, but by analogy; thus a claw is analogous to a thorn, and a nail to a hoof, and a hand to the nipper of a lobster, and a feather to a scale; for what a feather is in a bird, that is a scale in a fish."

[Note 126\16: Lib. i. c. i.]

It will not, however, be necessary, in order to understand Aristotle for our present purpose, that we should discuss his notion of Analogy. He proceeds to state his object,[127\16] which is, as we have said, to describe the differences of animals in their structure and habits. He then observes, that for structure, we may take Man for our type,[128\16] as being best known to us; and the remainder of the first Book is occupied with a description of man's body, beginning from the head, and proceeding to the extremities.

[Note 127\16: Lib. i. c. ii.]

[Note 128\16: c. iii.]

In the next Book, (from which are taken the principal passages in which his modern commentators detect his system,) he proceeds to compare the differences of parts in different animals, according to the order which he had observed in man. In the first chapter he speaks {414} of the head and neck of animals; in the second, of the parts analogous to arms and hands; in the third, of the breast and paps, and so on; and thus he comes, in the seventh chapter, to the legs, feet, and toes: and in the eleventh, to the teeth, and so to other parts.

The construction of a classification consists in the selection of certain parts, as those which shall eminently and peculiarly determine the place of each species in our arrangement. It is clear, therefore, that such an enumeration of differences as we have described, supposing it complete, contains the materials of all possible classifications. But we can with no more propriety say that the author of such an enumeration of differences is the author of any classification which can be made by means of them, than we can say that a man who writes down the whole alphabet writes down the solution of a given riddle or the answer to a particular question.

Yet it is on no other ground than this enumeration, so far as I can discover, that Aristotle's "System" has been so decidedly spoken of,[129\16] and exhibited in the most formal tabular shape. The authors of this Systema Aristotelicum, have selected, I presume, the following passages from the work On Animals, as they might have selected any other; and by arranging them according to a subordination unknown to Aristotle himself have made for him a scheme which undoubtedly bears a great resemblance to the most complete systems of modern times.

[Note 129\16: Linnæan Transactions, vol. xvi. p. 24.]

Book I., chap. v.--"Some animals are viviparous, some oviparous, some vermiparous. The viviparous are such as man, and the horse, and all those animals which have hair; and of aquatic animals, the whale kind, as the dolphin and cartilaginous fishes."

Book II., chap. vii.--"Of quadrupeds which have blood and are viviparous, some are (as to their extremities,) many-cloven, as the hands and feet of man. For some are many-toed, as the lion, the dog, the panther; some are bifid, and have hoofs instead of nails, as the sheep, the goat, the elephant, the hippopotamus; and some have undivided feet, as the solid-hoofed animals, the horse and ass. The swine kind share both characters."

Chap. ii.--"Animals have also great differences in the teeth, both when compared with each other and with man. For all quadrupeds which have blood and are viviparous, have teeth. And in the first place, some are ambidental,[130\16] (having teeth in both jaws;) and some {415} are not so, wanting the front teeth in the upper jaw. Some have neither front teeth nor horns, as the camel; some have tusks,[131\16] as the boar, some have not. Some have serrated[132\16] teeth, as the lion, the panther, the dog; some have the teeth unvaried,[133\16] as the horse and the ox; for the animals which vary their cutting-teeth have all serrated teeth. No animal has both tusks and horns; nor has any animal with serrated teeth either of those weapons. The greater part have the front teeth cutting, and those within broad."

[Note 130\16: Ἀμφόδοντα.]

[Note 131\16: Χαυλιόδοντα.]

[Note 132\16: Καρχαρόδοντα.]

[Note 133\16: Ἀνεπάλλακτα.]

These passages undoubtedly contain most of the differences on which the asserted Aristotelian classification rests; but the classification is formed by using the characters drawn from the teeth, in order to subdivide those taken from the feet; whereas in Aristotle these two sets of characters stand side by side, along with dozens of others; any selection of which, employed according to any arbitrary method of subordination, might with equal justice be called Aristotle's system.

Why, for instance, in order to form subdivisions of animals, should we not go on with Aristotle's continuation of the second of the above quoted passages, instead of capriciously leaping to the third? "Of these some have horns, some have none . . . Some have a fetlock-joint,[134\16] some have none . . . Of those which have horns, some have them solid throughout, as the stag; others, for the most part, hollow . . . Some cast their horns, some do not." If it be replied, that we could not, by means of such characters, form a tenable zoological system; we again ask by what right we assume Aristotle to have made or attempted a systematic arrangement, when what he has written, taken in its natural order, does not admit of being construed into a system.

[Note 134\16: Ἀστράγαλον.]

Again, what is the object of any classification? This, at least, among others. To enable the person who uses it to study and describe more conveniently the objects thus classified. If, therefore, Aristotle had formed or adopted any system of arrangement, we should see it in the order of the subjects in his work. Accordingly, so far as he has a system, he professes to make this use of it. At the beginning of the fifth Book, where he is proceeding to treat of the different modes of generation of animals, he says, "As we formerly made a Division of animals according to their kinds, we must now, in the same manner, give a general survey of their History (θεωρίαν). Except, indeed, that in the former case we made our commencement by a description {416} of man, but in the present instance we must speak of him last, because he requires most study. We must begin then with those animals which have shells; we must go on to those which have softer coverings, as crustacea, soft animals, and insects; after these, fishes, both viviparous and oviparous; then birds; then land animals, both viviparous and oviparous."

It is clear from this passage that Aristotle had certain wide and indefinite views of classification, which though not very exact, are still highly creditable to him; but it is equally clear that he was quite unconscious of the classification that has been ascribed to him. If he had adopted that or any other system, this was precisely the place in which he must have referred to and employed it.

The honor due to the stupendous accumulation of zoological knowledge which Aristotle's works contain, cannot be tarnished by our denying him the credit of a system which he never dreamt of and which, from the nature of the progress of science, could not possibly be constructed at that period. But, in reality, we may exchange the mistaken claims which we have been contesting for a better, because a truer praise. Aristotle does show, as far as could be done at his time, a perception of the need of groups, and of names of groups, in the study of the animal kingdom; and thus may justly be held up as the great figure in the Prelude to the Formation of Systems which took place in more advanced scientific times.

This appears, in some measure, from the passage last quoted. For not only is there, in that, a clear recognition of the value and object of a method in natural history; but the general arrangement of the animal kingdom there proposed has considerable scientific merit, and is, for the time, very philosophical. But there are passages in his work in which he shows a wish to carry the principle of arrangement more into detail. Thus, in the first Book, before proceeding to his survey of the differences of animals,[135\16] after speaking of such classes as Quadrupeds. Birds, Fishes, Cetaceous, Testaceous, Crustaceous Animals, Mollusks, Insects, he says, (chap. vii.) "Animals cannot be divided into large genera, in which one kind includes many kinds. For some kinds are unique, and have no difference of species, as man. Some have such kinds, but have no names for them. Thus all quadrupeds which have not wings, have blood. But of these, some are viviparous, some oviparous. Those which are {417} viviparous have not all hair; those which are oviparous have scales." We have here a manifestly intentional subordination of characters: and a kind of regret that we have not names for the classes here indicated; such, for instance, as viviparous quadrupeds having hair. But he follows the subject into further detail. "Of the class of viviparous quadrupeds," he continues, "there are many genera,[136\16] but these again are without names, except specific names, such as man, lion, stag, horse, dog, and the like. Yet there is a genus of animals that have names, as the horse, the ass, the oreus, the ginnus, the innus, and the animal which in Syria is called heminus (mule); for these are called mules, from their resemblance only; not being mules, for they breed of their own kind. Wherefore," he adds, that is, because we do not possess recognized genera and generic names of this kind, "we must take the species separately, and study the nature of each."

[Note 135\16: Γένη.]

[Note 136\16: **Εἴδη.]

These passages afford us sufficient ground for placing Aristotle at the head of those naturalists to whom the first views of the necessity of a zoological system are due. It was, however, very long before any worthy successor appeared, for no additional step was made till modern times. When Natural History again came to be studied in Nature, the business of Classification, as we have seen, forced itself upon men's attention, and was pursued with interest in animals, as in plants. The steps of its advance were similar in the two cases;--by successive naturalists, various systems of artificial marks were selected with a view to precision and convenience;--and these artificial systems assumed the existence of certain natural groups, and of a natural system to which they gradually tended. But there was this difference between botany and zoology:--the reference to physiological principles, which, as we have remarked, influenced the natural systems of vegetables in a latent and obscure manner, botanists being guided by its light, but hardly aware that they were so, affected the study of systematic zoology more directly and evidently. For men can neither overlook the general physiological features of animals, nor avoid being swayed by them in their judgments of the affinities of different species. Thus the classifications of zoology tended more and more to a union with comparative anatomy, as the science was more and more improved.[137\16] But comparative anatomy belongs to the subject of the next Book; and anything it may be proper to say respecting its influence upon zoological arrangements, will properly find a place there. {418}

[Note 137\16: Cuvier, Leç. d'Anat. Comp. vol. i. p. 17.]

It will appear, and indeed it hardly requires to be proved, that those steps in systematic zoology which are due to the light thrown upon the subject by physiology, are the result of a long series of labors by various naturalists, and have been, like other advances in science, led to and produced by the general progress of such knowledge. We can hardly expect that the classificatory sciences can undergo any material improvement which is not of this kind. Very recently, however, some authors have attempted to introduce into these sciences certain principles which do not, at first sight, appear as a continuation and extension of the previous researches of comparative anatomists. I speak, in particular, of the doctrines of a Circular Progression in the series of affinity; of a Quinary Division of such circular groups; and of a relation of Analogy between the members of such groups, entirely distinct from the relation of Affinity.

The doctrine of Circular Progression has been propounded principally by Mr. Macleay; although, as he has shown,[138\16] there are suggestions of the same kind to be found in other writers. So far as this view negatives the doctrine of a mere linear progression in nature, which would place each genus in contact only with the preceding and succeeding ones, and so far as it requires us to attend to more varied and ramified resemblances, there can be no doubt that it is supported by the result of all the attempts to form natural systems. But whether that assemblage of circles of arrangement which is now offered to naturalists, be the true and only way of exhibiting the natural relations of organized bodies, is a much more difficult question, and one which I shall not here attempt to examine; although it will be found, I think, that those analogies of science which we have had to study, would not fail to throw some light upon such an inquiry. The prevalence of an invariable numerical law in the divisions of natural groups, (as the number five is asserted to prevail by Mr. Macleay, the number ten by Fries, and other numbers by other writers), would be a curious fact, if established; but it is easy to see that nothing short of the most consummate knowledge of natural history, joined with extreme clearness of view and calmness of judgment, could enable any one to pronounce on the attempts which have been made to establish such a principle. But the doctrine of a relation of Analogy distinct from Affinity, in the manner which has recently been taught, seems to be obviously at variance with that gradual approximation of the classificatory to the {419} physiological sciences, which has appeared to us to be the general tendency of real knowledge. It seems difficult to understand how a reference to such relations as those which are offered as examples of analogy[139\16] can be otherwise than a retrograde step in science.

[Note 138\16: Linn. Trans. vol. xvi. p. 9.]

[Note 139\16: For example, the goatsucker has an affinity with the swallow; but it has an analogy with the bat, because both fly at the same hour of the day, and feed in the same manner.--Swainson, Geography and Classification of Animals, p. 129.]

Without, however, now dwelling upon these points, I will treat a little more in detail of one of the branches of Zoology.

[2nd Ed.] [For the more recent progress of Systematic Zoology, see in the Reports of the British Association, in 1834, Mr. L. Jenyns's Report an the Recent Progress and Present State of Zoology, and in 1844, Mr. Strickland's Report on the Recent Progress and Present State of Ornithology. In these Reports, the questions of the Circular Arrangement, the Quinary System, and the relation of Analogy and Affinity are discussed.]

VII. THE PROGRESS OF ICHTHYOLOGY

IF it had been already observed and admitted that sciences of the same kind follow, and must follow, the same course in the order of their development, it would be unnecessary to give a history of any special branch of Systematic Zoology; since botany has already afforded us a sufficient example of the progress of the classificatory sciences. But we may be excused for introducing a sketch of the advance of one department of zoology, since we are led to the attempt by the peculiar advantage we possess in having a complete history of the subject written with great care, and brought up to the present time, by a naturalist of unequalled talents and knowledge. I speak of Cuvier's Historical View of Ichthyology, which forms the first chapter of his great work on that part of natural history. The place and office in the progress of this science, which is assigned to each person by Cuvier, will probably not be lightly contested. It will, therefore, be no small confirmation of the justice of the views on which the {420} distribution of the events in the history of botany was founded, if Cuvier's representation of the history of ichthyology offers to us obviously a distribution almost identical.

We shall find that this is so;--that we have, in zoology as in botany, a period of unsystematic knowledge; a period of misapplied erudition; an epoch of the discovery of fixed characters; a period in which many systems were put forward; a struggle of an artificial and a natural method; and a gradual tendency of the natural method to a manifestly physiological character. A few references to Cuvier's history will enable us to illustrate these and other analogies.

Period of Unsystematic Knowledge.--It would be easy to collect a number of the fabulous stories of early times, which formed a portion of the imaginary knowledge of men concerning animals as well as plants. But passing over these, we come to a long period and a great collection of writers, who, in various ways, and with various degrees of merit, contributed to augment the knowledge which existed concerning fish, while as yet there was hardly ever any attempt at a classification of that province of the animal kingdom. Among these writers, Aristotle is by far the most important. Indeed he carried on his zoological researches under advantages which rarely fall to the lot of the naturalist; if it be true, as Athenæus and Pliny state,[140\16] that Alexander gave him sums which amounted to nine hundred talents, to enable him to collect materials for his history of animals, and put at his disposal several thousands of men to be employed in hunting, fishing, and procuring information for him. The works of his on Natural History which remain to us are, nine Books Of the History of Animals; four, On the Parts of Animals; five, On the Generation of Animals; one, On the Going of Animals; one, Of the Sensations, and the Organs of them; one, On Sleeping and Waking; one, On the Motion of Animals; one, On the Length and Shortness of Life; one, On Youth and Old Age; one, On Life and Death; one, On Respiration. The knowledge of the external and internal conformation of animals, their habits, instincts, and uses, which Aristotle displays in these works, is spoken of as something wonderful even to the naturalists of our own time. And he may be taken as a sufficient representative of the whole of the period of which we speak; for he is, says Cuvier,[141\16] not only the first, but the only one of the ancients who has treated of the natural history of fishes (the province to which {421} we now confine ourselves,) in a scientific point of view, and in a way which shows genius.

[Note 140\16: Cuv. Hist. Nat. des Poissons, i. 13.]

[Note 141\16: Cuv. p. 18.]

We may pass over, therefore, the other ancient authors from whose writings Cuvier, with great learning and sagacity, has levied contributions to the history of ichthyology; as Theophrastus, Ovid, Pliny, Oppian, Athenæus, Ælian, Ausonius, Galen. We may, too, leave unnoticed the compilers of the middle ages, who did little but abstract and disfigure the portions of natural history which they found in the ancients. Ichthyological, like other knowledge, was scarcely sought except in books, and on that very account was not understood when it was found.

Period of Erudition.--Better times at length came, and men began to observe nature for themselves. The three great authors who are held to be the founders of modern ichthyology, appeared in the middle of the sixteenth century; these were Bélon, Rondelet, and Salviani, who all published about 1555. All the three, very different from the compilers who filled the interval from Aristotle to them, themselves saw and examined the fishes which they describe, and have given faithful representations of them. But, resembling in that respect the founders of modern botany, Briassavola, Ruellius, Tragus, and others, they resembled them in this also, that they attempted to make their own observations a commentary upon the ancient writers. Faithful to the spirit of their time, they are far more careful to make out the names which each fish bore in the ancient world, and to bring together scraps of their history from the authors in whom these names occur, than to describe them in a lucid manner; so that without their figures, says Cuvier, it would be almost as difficult to discover their species as those of the ancients.

The difficulty of describing and naming species so that they can be recognized, is little appreciated at first, although it is in reality the main-spring of the progress of the sciences of classification. Aristotle never dreamt that the nomenclature which was in use in his time could ever become obscure;[142\16] hence he has taken no precaution to enable his readers to recognize the species of which he speaks; and in him and in other ancient authors, it requires much labor and great felicity of divination to determine what the names mean. The perception of this difficulty among modern naturalists led to systems, and to nomenclature founded upon system; but these did not come into {422} being immediately at the time of which we speak; nor till the evil had grown to a more inconvenient magnitude.

[Note 142\16: Cuvier, p. 17.]

Period of Accumulation of Materials. Exotic Collections.--The fishes of Europe were for some time the principal objects of study; but those of distant regions soon came into notice.[143\16] In the seventeenth century the Dutch conquered Brazil, and George Margrave, employed by them, described the natural productions of the country, and especially the fishes. Bontius, in like manner, described some of those of Batavia. Thus these writers correspond to Romphius and Rheede in the history of botany. Many others might be mentioned; but we must hasten to the formation of systems, which is our main object of attention.

[Note 143\16: Cuv. p. 43.]

Epoch of the Fixation of Characters. Ray and Willoughby.--In botany, as we have seen, though Ray was one of the first who invented a connected system, he was preceded at a considerable interval by Cæsalpinus, who had given a genuine solution of the same problem. It is not difficult to assign reasons why a sound classification should be discovered for plants at an earlier period than for fishes. The vastly greater number of the known species, and the facilities which belong to the study of vegetables, give the botanist a great advantage; and there are numerical relations of a most definite kind (for instance, the number of parts of the seed-vessel employed by Cæsalpinus as one of the bases of his system), which are tolerably obvious in plants, but which are not easily discovered in animals. And thus we find that in ichthyology, Ray, with his pupil and friend Willoughby, appears as the first founder of a tenable system.[144\16]

[Note 144\16: Francisci Willoughbeii, Armigeri, de Historia Piscium, libri iv. jussu et sumptibus Societatis Regiæ Londinensis editi, &c. Totum opus recognovit, coaptavit, supplevit, librum etiam primum et secundum adjecit Joh. Raius. Oxford, 1668.]

The first great division in this system is into cartilaginous and bony fishes; a primary division, which had been recognized by Aristotle, and is retained by Cuvier in his latest labors. The subdivisions are determined by the general form of the fish (as long or flat), by the teeth, the presence or absence of ventral fins, the number of dorsal fins, and the nature of the spines of the fins, as soft or prickly. Most of these characters have preserved their importance in later systems; especially the last, which, under the terms malacopterygian and acanthopterygian, holds a place in the best recent arrangements. {423}

That this system was a true first approximation to a solution of the problem, appears to be allowed by naturalists. Although, says Cuvier,[145\16] there are in it no genera well defined and well limited, still in many places the species are brought together very naturally, and in such a way that a few words of explanation would suffice to form, from the groups thus presented to us, several of the genera which have since been received. Even in botany, as we have seen, genera were hardly maintained with any degree of precision, till the binary nomenclature of Linnæus made this division a matter of such immense convenience.

[Note 145\16: Cuvier, p. 57.]

The amount of this convenience, the value of a brief and sure nomenclature, had not yet been duly estimated. The work of Willoughby forms an epoch,[146\16] and a happy epoch, in the history of ichthyology; for the science, once systematized, could distinguish the new from the old, arrange methodically, describe clearly. Yet, because Willoughby had no nomenclature of his own, and no fixed names for his genera, his immediate influence was not great. I will not attempt to trace this influence in succeeding authors, but proceed to the next important step in the progress of system.

[Note 146\16: p. 58.]

Improvement of the System. Artedi.--Peter Artedi was a countryman and intimate friend of Linnæus; and rendered to ichthyology nearly the same services which Linnæus rendered to botany. In his Philosophia Ichthyologica, he analysed[147\16] all the interior and exterior parts of animals; he created a precise terminology for the different forms of which these parts are susceptible; he laid down rules for the nomenclature of genera and species; besides his improvements of the subdivisions of the class. It is impossible not to be struck with the close resemblance between these steps, and those which are due to the Fundamenta Botanica. The latter work appeared in 1736, the former was published by Linnæus, after the death of the author, in 1738; but Linnæus had already, as early as 1735, made use of Artedi's manuscripts in the ichthyological part of his Systema Naturæ. We cannot doubt that the two young naturalists (they were nearly of the same age), must have had a great influence upon each other's views and labors; and it would be difficult now to ascertain what portion of the peculiar merits of the Linnæan reform was derived from Artedi. But we may remark that, in ichthyology at least, Artedi appears to have been a naturalist of more original views and profounder philosophy than his friend and editor, who afterwards himself took up the subject. {424} The reforms of Linnæus, in all parts of natural history, appear as if they were mainly dictated by a love of elegance, symmetry, clearness, and definiteness; but the improvement of the ichthyological system by Artedi seems to have been a step in the progress to a natural arrangement. His genera,[148\16] which are forty-five in number, are so well constituted, that they have almost all been preserved; and the subdivisions which the constantly-increasing number of species has compelled his successors to introduce, have very rarely been such that they have led to the transposition of his genera.

[Note 147\16: p. 20.]

[Note 148\16: Cuvier, p. 71.]

In its bases, however, Artedi's was an artificial system. His characters were positive and decisive, founded in general upon the number of rays of the membrane of the gills, of which he was the first to mark the importance;--upon the relative position of the fins, upon their number, upon the part of the mouth where the teeth are found, upon the conformation of the scales. Yet, in some cases, he has recourse to the interior anatomy.

Linnæus himself at first did not venture to deviate from the footsteps of a friend, who, in this science, had been his master. But in 1758, in the tenth edition of the Systema Naturæ, he chose to depend upon himself and devised a new ichthyological method. He divided some genera, united others, gave to the species trivial names and characteristic phrases, and added many species to those of Artedi. Yet his innovations are for the most part disapproved of by Cuvier; as his transferring the chondropterygian fishes of Artedi to the class of reptiles, under the title of Amphybia nantes; and his rejecting the distinction of acanthopterygian and malacopterygian, which, as we have seen, had prevailed from the time of Willoughby, and introducing in its stead a distribution founded on the presence or absence of the ventral fins, and on their situation with regard to the pectoral fins. "Nothing," says Cuvier, "more breaks the true connexions of genera than these orders of apodes, jugulares, thoracici, and abdominales."

Thus Linnæus, though acknowledging the value and importance of natural orders, was not happy in his attempts to construct a system which should lead to them. In his detection of good characters for an artificial system he was more fortunate. He was always attentive to number, as a character; and he had the very great merit[149\16] of introducing into the classification the number of rays of the fins of each species. This mark is one of great importance and use. And this, as well as {425} other branches of natural history, derived incalculable advantages from the more general merits of the illustrious Swede;[150\16]--the precision of the characters, the convenience of a well-settled terminology, the facility afforded by the binary nomenclature. These recommendations gave him a pre-eminence which was acknowledged by almost all the naturalists of his time, and displayed by the almost universal adoption of his nomenclature, in zoology, as well as in botany; and by the almost exclusive employment of his distributions of classes, however imperfect and artificial they might be.

[Note 149\16: p. 74.]

[Note 150\16: Cuvier, p. 85.]

And even[151\16] if Linnæus had had no other merit than the impulse he gave to the pursuit of natural science, this alone would suffice to immortalize his name. In rendering natural history easy, or at least in making it appear so, he diffused a general taste for it. The great took it up with interest; the young, full of ardor, rushed forwards in all directions, with the sole intention of completing his system. The civilized world was eager to build the edifice which Linnæus had planned.

[Note 151\16: Ib. p. 88.]

This spirit, among other results, produced voyages of natural historical research, sent forth by nations and sovereigns. George the Third of England had the honor of setting the example in this noble career, by sending out the expeditions of Byron, Wallis, and Carteret, in 1765. These were followed by those of Bougainville, Cook, Forster, and others. Russia also scattered several scientific expeditions through her vast dominions; and pupils of Linnæus sought the icy shores of Greenland and Iceland, in order to apply his nomenclature to the productions of those climes. But we need not attempt to convey any idea of the vast stores of natural historical treasures which were thus collected from every part of the globe.

I shall not endeavor to follow Cuvier in giving an account of the great works of natural history to which this accumulation of materials gave rise; such as the magnificent work of Bloch on Fishes, which appeared in 1782-1785; nor need I attempt, by his assistance, to characterize or place in their due position the several systems of classification proposed about this time. But in the course of these various essays, the distinction of the artificial and natural methods of classification came more clearly into view than before; and this is a point so important to the philosophy of the subject, that we must devote a few words to it. {426}

Separation of the Artificial and Natural Methods in Ichthyology.--It has already been said that all so-called artificial methods of classification must be natural, at least as to the narrowest members of the system; thus the artificial Linnæan method is natural as to species, and even as to genera. And on the other hand, all proposed natural methods, so long as they remain unmodified, are artificial as to their characteristic marks. Thus a Natural Method is an attempt to provide positive and distinct characters for the wider as well as for the narrower natural groups. These considerations are applicable to zoology as well as to botany. But the question, how we know natural groups before we find marks for them, was, in botany, as we have seen, susceptible only of vague and obscure answers:--the mind forms them, it was said, by taking the aggregate of all the characters; or by establishing a subordination of characters. And each of these answers had its difficulty, of which the solution appeared to be, that in attempting to form natural orders we are really guided by a latent undeveloped estimate of physiological relations. Now this principle, which was so dimly seen in the study of vegetables, shines out with much greater clearness when we come to the study of animals, in which the physiological relations of the parts are so manifest that they cannot be overlooked, and have so strong an attraction for our curiosity that we cannot help having our judgments influenced by them. Hence the superiority of natural systems in zoology would probably be far more generally allowed than in botany; and no arrangement of animals which, in a large number of instances, violated strong and clear natural affinities, would be tolerated because it answered the purpose of enabling us easily to find the name and place of the animal in the artificial system. Every system of zoological arrangement may be supposed to aspire to be a natural system. But according to the various habits of the minds of systematizers, this object was pursued more or less steadily and successfully; and these differences came more and more into view with the increase of knowledge and the multiplication of attempts.

Bloch, whose ichthyological labors have been mentioned, followed in his great work the method of Linnæus. But towards the end of his life he had prepared a general system, founded upon one single numerical principle;--the number of fins; just as the sexual system of Linnæus is founded upon the number of stamina; and he made his subdivisions according to the position of the ventral and pectoral fins; the same character which Linnæus had employed for his primary {427} division. He could not have done better, says Cuvier,[152\16] if his object had been to turn into ridicule all artificial methods, and to show to what absurd combinations they may lead.

[Note 152\16: p. 108.]

Cuvier himself who always pursued natural systems with a singularly wise and sagacious consistency, attempted to improve the ichthyological arrangements which had been proposed before him. In his Règne Animal, published in 1817, he attempts the problem of arranging this class; and the views suggested to him, both by his successes and his failures, are so instructive and philosophical, that I cannot illustrate the subject better than by citing some of them.

"The class of fishes," he says,[153\16] "is, of all, that which offers the greatest difficulties, when we wish to subdivide it into orders, according to fixed and obvious characters. After many trials, I have determined on the following distribution, which in some instances is wanting in precision, but which possesses the advantage of keeping the natural families entire.

[Note 153\16: Règne Animal, vol. ii. p. 110.]

"Fish form two distinct series;--that of chondropterygians or cartilaginous fish, and that of fish properly so called.

"The first of these series has for its character, that the palatine bones replace, in it, the bones of the upper jaw: moreover the whole of its structure has evident analogies, which we shall explain.

"It divides itself into three ORDERS: "The CYCLOSTOMES, in which the jaws are soldered (soudées) into an immovable ring, and the bronchiæ are open in numerous holes.

"The SELACIANS, which have the bronchiæ like the preceding, but not the jaws.

"The STURONIANS, in which the bronchiæ are open as usual by a slit furnished with an operculum.

"The second series, or that of ordinary fishes, offers me, in the first place, a primary division, into those of which the maxillary bone and the palatine arch are dovetailed (engrenés) to the skull. Of these I make an order of PECTOGNATHS, divided into two families; the gymnodonts and the scleroderms.

"After these I have the fishes with complete jaws, but with bronchiæ which, instead of having the form of combs, as in all the others, have the form of a series of little tufts (houppes). Of these I again form an order, which I call LOPHOBRANCHS, which only includes one family. {428}

"There then remains an innumerable quantity of fishes, to which we can no longer apply any characters except those of the exterior organs of motion. After long examination, I have found that the least bad of these characters is, after all, that employed by Ray and Artedi, taken from the nature of the first rays of the dorsal and of the anal fin. Thus ordinary fishes are divided into MALACOPTERYGIANS, of which all the rays are soft, except sometimes the first of the dorsal fin or the pectorals;--and ACANTHOPTERYGIANS, which have always the first portion of the dorsal, or of the first dorsal when there are two, supported by spinous rays, and in which the anal has also some such rays, and the ventrals, at least, each one.

"The former may be subdivided without inconvenience, according to their ventral fins, which are sometimes situate behind the abdomen, sometimes adherent to the apparatus of the shoulder, or, finally, are sometimes wanting altogether.

"We thus arrive at the three orders of ABDOMINAL MALACOPTERYGIANS, of SUBBRACHIANS, and of APODES; each of which includes some natural families which we shall explain: the first, especially, is very numerous.

"But this basis of division is absolutely impracticable with the Acanthopterygians; and the problem of establishing among these any other subdivision than that of the natural families has hitherto remained for me insoluble. Fortunately several of these families offer characters almost as precise as those which we could give to true orders.

"In truth, we cannot assign to the families of fishes, ranks as marked, as for example, to those of mammifers. Thus the Chondropterygians on the one hand hold to reptiles by the organs of the senses, and by those of generation in some; and they are related to mollusks and worms by the imperfection of the skeleton in others.

"As to Ordinary Fishes, if any part of the organization is found more developed in some than in others, there does not result from this any pre-eminence sufficiently marked, or of sufficient influence upon their whole system, to oblige us to consult it in the methodical arrangement.

"We shall place them, therefore, nearly in the order in which we have just explained their characters."

I have extracted the whole of this passage, because, though it is too technical to be understood in detail by the general reader, those who have followed with any interest the history of the attempts at a natural classification in any department in nature, will see here a fine example of the problems which such attempts propose, of the {429} difficulties which it may present, and of the reasonings, labors, cautions, and varied resources, by means of which its solution is sought, when a great philosophical naturalist girds himself to the task. We see here, most instructively, how different the endeavor to frame such a natural system, is from the procedure of an artificial system, which carries imperatively through the whole of a class of organized beings, a system of marks either arbitrary, or conformable to natural affinities in a partial degree. And we have not often the advantage of having the reasons for a systematic arrangement so clearly and fully indicated, as is done here, and in the descriptions of the separate orders.

This arrangement Cuvier adhered to in all its main points, both in the second edition of the Règne Animal, published in 1821, and in his Histoire Naturelle des Poissons, of which the first volume was published in 1828, but which unfortunately was not completed at the time of his death. It may be supposed, therefore, to be in accordance with those views of zoological philosophy, which it was the business of his life to form and to apply; and in a work like the present, where, upon so large a question of natural history, we must be directed in a great measure by the analogy of the history of science, and by the judgments which seem most to have the character of wisdom, we appear to be justified in taking Cuvier's ichthyological system as the nearest approach which has yet been made to a natural method in that department.

The true natural method is only one: artificial methods, and even good ones, there may be many, as we have seen in botany; and each of these may have its advantages for some particular use. On some methods of this kind, on which naturalists themselves have hardly yet had time to form a stable and distinct opinion, it is not our office to decide. But judging, as I have already said, from the general analogy of the natural sciences, I find it difficult to conceive that the ichthyological method of M. Agassiz, recently propounded with an especial reference to fossil fishes, can be otherwise than an artificial method. It is founded entirely on one part of the animal, its scaly covering, and even on a single scale. It does not conform to that which almost all systematic ichthyologists hitherto have considered as a permanent natural distinction of a high order; the distinction of bony and cartilaginous fishes; for it is stated that each order contains examples of both.[154\16] I do not know what general anatomical or physiological {430} truths it brings into view; but they ought to be very important and striking ones, to entitle them to supersede those which led Cuvier to his system. To this I may add, that the new ichthyological classification does not seem to form, as we should expect that any great advance towards a natural system would form, a connected sequel to the past history of ichthyology;--a step to which anterior discoveries and improvements have led, and in which they are retained.

[Note 154\16: Dr. Buckland's Bridgewater Treatise, p. 270.]

But notwithstanding these considerations, the method of M. Agassiz has probably very great advantages for his purpose; for in the case of fossil fish, the parts which are the basis of his system often remain, when even the skeleton is gone. And we may here again refer to a principle of the classificatory sciences which we cannot make too prominent;--all arrangements and nomenclatures are good, which enable us to assert general propositions. Tried by this test, we cannot fail to set a high value on the arrangement of M. Agassiz; for propositions of the most striking generality respecting fossil remains of fish, of which geologists before had never dreamt, are enunciated by means of his groups and names. Thus only the two first orders, the Placoïdians and Ganoïdians, existed before the commencement of the cretaceous formation: the third and fourth orders, the Ctenoïdians and Cycloïdians, which contain three-fourths of the eight thousand known species of living Fishes, appear for the first time in the cretaceous formation: and other geological relations of these orders, no less remarkable, have been ascertained by M. Agassiz.

But we have now, I trust, pursued these sciences of classification sufficiently far; and it is time for us to enter upon that higher domain of Physiology to which, as we have said. Zoology so irresistibly directs us.

[2nd Ed.] [I have retained the remarks which I ventured at first to make on the System of M. Agassiz; but I believe the opinion of the most philosophical ichthyologists to be that Cuvier's System was too exclusively based on the internal skeleton, as Agassiz's was on the external skeleton. In some degree both systems have been superseded, while all that was true in each has been retained. Mr. Owen, in his Lectures on Vertebrata (1846), takes Cuvierian characters from the endo-skeleton, Agassizian ones from the exo-skeleton, Linnæan ones from the ventral fins, Müllerian ones from the air-bladder, and combines them by the light of his own researches, with the view of forming a system more truly natural than any preceding one.

As I have said above, naturalists, in their progress towards a Natural {431} System, are guided by physiological relations, latently in Botany, but conspicuously in Zoology. From the epoch of Cuvier's Règne Animal, the progress of Systematic Zoology is inseparably dependent on the progress of Comparative Anatomy. Hence I have placed Cuvier's Classification of animal forms in the next Book, which treats of Physiology.]

{{433}} BOOK XVII.

ORGANICAL SCIENCES.

HISTORY OF PHYSIOLOGY AND COMPARATIVE ANATOMY.

Fearful and wondrous is the skill which moulds Our body's vital plan, And from the first dim hidden germ unfolds The perfect limbs of man. Who, who can pierce the secret? tell us how Something is drawn from naught, Life from the inert mass? Who, Lord! but thou, Whose hand the whole has wrought? Of this corporeal substance, still to be, Thine eye a survey took; And all my members, yet unformed by thee, Were written in thy book. PSALM cxxxix. 13-16.

{{435}} INTRODUCTION.

Of the Organical Sciences

THOUGH the general notion of life is acknowledged by the most profound philosophers to be dim and mysterious, even up to the present time; and must, in the early stages of human speculation, have been still more obscure and confused; it was sufficient, even then, to give interest and connexion to men's observations upon their own bodies and those of other animals. It was seen, that in living things, certain peculiar processes were constantly repeated, as those of breathing and of taking food, for example; and that a certain conformation of the parts of the animal was subservient to these processes; and thus were gradually formed the notions of Function and of Organization. And the sciences of which these notions formed the basis are clearly distinguishable from all those which we have hitherto considered. We conceive an organized body to be one in which the parts are there for the sake of the whole, in a manner different from any mechanical or chemical connexion; we conceive a function to be not merely a process of change, but of change connected with the general vital process. When mechanical or chemical processes occur in the living body, they are instrumental to, and directed by, the peculiar powers of life. The sciences which thus consider organization and vital functions may be termed organical sciences.

When men began to speculate concerning such subjects, the general mode of apprehending the process in the cases of some functions, appeared to be almost obvious; thus it was conceived that the growth of animals arose from their frame appropriating to itself a part of the substance of the food through the various passages of the body. Under the influence of such general conceptions, speculative men were naturally led to endeavor to obtain more clear and definite views of the course of each of such processes, and of the mode in which the separate parts contributed to it. Along with the observation of the living person, the more searching examination which could be carried on in the dead body, and the comparison of various kinds of animals, soon showed that this pursuit was rich in knowledge and in interest. {436} Moreover, besides the interest which the mere speculative faculty gave to this study, the Art of Healing added to it a great practical value; and the effects of diseases and of medicines supplied new materials and new motives for the reasonings of the philosopher.

In this manner anatomy or physiology may be considered as a science which began to be cultivated in the earliest periods of civilization. Like most other ancient sciences, its career has been one of perpetual though variable progress; and as in others, so in this, each step has implied those which had been previously made, and cannot be understood aright except we understand them. Moreover, the steps of this advance have been very many and diverse; the cultivators of anatomy have in all ages been numerous and laborious; the subject is one of vast extent and complexity; almost every generation had added something to the current knowledge of its details; and the general speculations of physiologists have been subtle, bold, and learned. It must, therefore, be difficult or impossible for a person who has not studied the science with professional diligence and professional advantages, to form just judgments of the value of the discoveries of various ages and persons, and to arrange them in their due relation to each other. To this we may add, that though all the discoveries which have been made with respect to particular functions or organizations are understood to be subordinate to one general science, the Philosophy of Life, yet the principles and doctrines of this science nowhere exist in a shape generally received and assented to among physiologists; and thus we have not, in this science, the advantage which in some others we have possessed;--of discerning the true direction of its first movements, by knowing the point to which they ultimately tend;--of running on beyond the earlier discoveries, and thus looking them in the face, and reading their true features. With these disadvantages, all that we can have to say respecting the history of Physiology must need great indulgence on the part of the reader.

Yet here, as in other cases, we may, by guiding our views by those of the greatest and most philosophical men who have made the subject their study, hope to avoid material errors. Nor can we well evade making the attempt. To obtain some simple and consistent view of the progress of physiological science, is in the highest degree important to the completion of our views of the progress of physical science. For the physiological or organical sciences form a class to which the classes already treated of, the mechanical, chemical, and classificatory sciences, are subordinate and auxiliary. Again, another {437} circumstance which makes physiology an important part of our survey of human knowledge is, that we have here a science which is concerned, indeed, about material combinations, but in which we are led almost beyond the borders of the material world, into the region of sensation and perception, thought and will. Such a contemplation may offer some suggestions which may prepare us for the transition from physical to metaphysical speculations.

In the survey which we must, for such purposes, take of the progress of physiology, it is by no means necessary that we should exhaust the subject, and attempt to give the history of every branch of the knowledge of the phenomena and laws of living creatures. It will be sufficient, if we follow a few of the lines of such researches, which may be considered as examples of the whole. We see that life is accompanied and sustained by many processes, which at first offer themselves to our notice as separate functions, however they may afterwards be found to be connected and identified; such are feeling, digestion, respiration, the action of the heart and pulse, generation, perception, voluntary motion. The analysis of any one of these functions may be pursued separately. And since in this, as in all genuine sciences, our knowledge becomes real and scientific, only in so far as it is verified in particular facts, and thus established in general propositions, such an original separation of the subjects of research is requisite to a true representation of the growth of real knowledge. The loose hypotheses and systems, concerning the connexion of different vital faculties and the general nature of living things, which have often been promulgated, must be excluded from this part of our plan. We do not deny all value and merit to such speculations; but they cannot be admitted in the earlier stages of the history of physiology, treated of as an inductive science. If the doctrine so propounded have a solid and permanent truth, they will again come before us when we have travelled through the range of more limited truths, and are prepared to ascend with security and certainty into the higher region of general physiological principles. If they cannot be arrived at by such a road, they are then, however plausible and pleasing, no portion of that real and progressive science with which alone our history is concerned.

We proceed, therefore, to trace the establishment of some of the more limited but certain doctrines of physiology. {438}

I. DISCOVERY OF THE ORGANS OF VOLUNTARY MOTION

Sect. 1.--Knowledge of Galen and his Predecessors.

IN the earliest conceptions which men entertained of their power of moving their own members, they probably had no thought of any mechanism or organization by which this was effected. The foot and the hand, no less than the head, were seen to be endowed with life; and this pervading life seemed sufficiently to explain the power of motion in each part of the frame, without its being held necessary to seek out a special seat of the will, or instruments by which its impulses were made effective. But the slightest inspection of dissected animals showed that their limbs were formed of a curious and complex collection of cordage, and communications of various kinds, running along and connecting the bones of the skeleton. These cords and communications we now distinguish as muscles, nerves, veins, arteries, &c.; and among these, we assign to the muscles the office of moving the parts to which they are attached, as cords move the parts of a machine. Though this action of the muscles on the bones may now appear very obvious, it was, probably, not at first discerned. It is observed that Homer, who describes the wounds which are inflicted in his battles with so much apparent anatomical precision, nowhere employs the word muscle. And even Hippocrates of Cos, the most celebrated physician of antiquity, is held to have had no distinct conception of such an organ.[1\17] He always employs the word flesh when he means muscle, and the first explanation of the latter word (μῦς) occurs in a spurious work ascribed to him. For nerves, sinews, ligaments,[2\17] he used indiscriminately the same terms; (τόνος or νεῦρον;) and of these nerves (νεῦρα) he asserts that they contract the limbs. Nor do we find much more distinctness on this subject even in Aristotle, a generation or two later. "The origin of the νεῦρα," he says,[3\17] "is from the heart; they connect {439} the bones, and surround the joints." It is clear that he means here the muscles, and therefore it is with injustice that he has been accused of the gross error of deriving the nerves from the heart. And he is held to have really had the merit[4\17] of discovering the nerves of sensation, which he calls the "canals of the brain" (πόροι τοῦ ἐγκεφάλου); but the analysis of the mechanism of motion is left by him almost untouched. Perhaps his want of sound mechanical notions, and his constant straining after verbal generalities, and systematic classifications of the widest kind, supply the true account of his thus missing the solution of one of the simplest problems of Anatomy.

[Note 1\17: Sprengel, Geschichte der Arzneikunde, i. 382.]

[Note 2\17: Sprengel, Gesch. Arz. i. 385.]

[Note 3\17: Hist. Anim. iii. 5.]

[Note 4\17: Ib. i. 456.]

In this, however, as in other subjects, his immediate predecessors were far from remedying the deficiencies of his doctrines. Those who professed to study physiology and medicine were, for the most part, studious only to frame some general system of abstract principles, which might give an appearance of connexion and profundity to their tenets. In this manner the successors of Hippocrates became a medical school, of great note in its day, designated as the Dogmatic school;[5\17] in opposition to which arose an Empiric sect, who professed to deduce their modes of cure, not from theoretical dogmas, but from experience. These rival parties prevailed principally in Asia Minor and Egypt, during the time of Alexander's successors,--a period rich in names, but poor in discoveries; and we find no clear evidence of any decided advance in anatomy, such as we are here attempting to trace.

[Note 5\17: Sprengel, Gesch. Arz. i. 583.]

The victories of Lucullus and Pompeius, in Greece and Asia, made the Romans acquainted with the Greek philosophy; and the consequence soon was, that shoals of philosophers, rhetoricians, poets, and physicians[6\17] streamed from Greece, Asia Minor, and Egypt, to Rome and Italy, to traffic their knowledge and their arts for Roman wealth. Among these, was one person whose name makes a great figure in the history of medicine, Asclepiades of Prusa in Bithynia. This man appears to have been a quack, with the usual endowments of his class;--boldness, singularity, a contemptuous rejection of all previously esteemed opinions, a new classification of diseases, a new list of medicines, and the assertion of some wonderful cures. He would not, on such accounts, deserve a place in the history of science, but that he became the founder of a new school, the Methodic, which professed to hold itself separate both from the Dogmatics and the Empirics. {440}

[Note 6\17: Sprengel, Gesch. Arz. ii. 5.]

I have noticed these schools of medicine, because, though I am not able to state distinctly their respective merits in the cultivation of anatomy, a great progress in that science was undoubtedly made during their domination, of which the praise must, I conceive, be in some way divided among them. The amount of this progress we are able to estimate, when we come to the works of Galen, who flourished under the Antonines, and died about A.D. 203. The following passage from his works will show that this progress in knowledge was not made without the usual condition of laborious and careful experiment, while it implies the curious fact of such experiment being conducted by means of family tradition and instruction, so as to give rise to a caste of dissectors. In the opening of his Second Book On Anatomical Manipulations, he speaks thus of his predecessors: "I do not blame the ancients, who did not write books on anatomical manipulation; though I praise Marinus, who did. For it was superfluous for them to compose such records for themselves or others, while they were, from their childhood, exercised by their parents in dissecting, just as familiarly as in writing and reading; so that there was no more fear of their forgetting their anatomy, than of forgetting their alphabet. But when grown men, as well as children, were taught, this thorough discipline fell off; and, the art being carried out of the family of the Asclepiads, and declining by repeated transmission, books became necessary for the student."

That the general structure of the animal frame, as composed of bones and muscles, was known with great accuracy before the time of Galen, is manifest from the nature of the mistakes and deficiencies of his predecessors which he finds it necessary to notice. Thus he observes, that some anatomists have made one muscle into two, from its having two heads;--that they have overlooked some of the muscles in the face of an ape, in consequence of not skinning the animal with their own hands;--and the like. Such remarks imply that the current knowledge of this kind was tolerably complete. Galen's own views of the general mechanical structure of an animal are very clear and sound. The skeleton, he observes, discharges[7\17] the office of the pole of a tent, or the walls of a house. With respect to the action of the muscles, his views were anatomically and mechanically correct; in some instances, he showed what this action was, by severing the muscle.[8\17] He himself added considerably to the existing knowledge of {441} this subject; and his discoveries and descriptions, even of very minute parts of the muscular system, are spoken of with praise by modern anatomists.[9\17]

[Note 7\17: De Anatom. Administ. i. 2.]

[Note 8\17: Sprengel, ii. 157.]

[Note 9\17: Sprengel, ii. 150.]

We may consider, therefore, that the doctrine of the muscular system, as a collection of cords and sheets, by the contraction of which the parts of the body are moved and supported, was firmly established, and completely followed into detail, by Galen and his predecessors. But there is another class of organs connected with voluntary motion, the nerves, and we must for a moment trace the opinions which prevailed respecting these. Aristotle, as we have said, noticed some of the nerves of sensation. But Herophilus, who lived in Egypt in the time of the first Ptolemy, distinguished nerves as the organs of the will,[10\17] and Rufus, who lived in the time of Trajan,[11\17] divides the nerves into sensitive and motive, and derives them all from the brain. But this did not imply that men had yet distinguished the nerves from the muscles. Even Galen maintained that every muscle consists of a bundle of nerves and sinews.[12\17] But the important points, the necessity of the nerve, and the origination of all this apparatus of motion from the brain, he insists upon with great clearness and force. Thus he proved the necessity experimentally, by cutting through some of the bundles of nerves,[13\17] and thus preventing the corresponding motions. And it is, he says,[14\17] allowed by all, both physicians and philosophers, that where the origin of the nerve is, there the seat of the soul (ἡγημονικὸν τῆς ψυχῆς) must be: now this, he adds, is in the brain, and not in the heart.

[Note 10\17: Ib. i. 534.]

[Note 11\17: Ib. ii. 67.]

[Note 12\17: Ibid. ii. 152. Galen, De Motu Musc., p. 553.]

[Note 13\17: Ib. 157.]

[Note 14\17: De Hippocr. et Plat. Dog. viii. 1.]

Thus the general construction and arrangement of the organization by which voluntary motion is effected, was well made out at the time of Galen, and is found distinctly delivered in his works. We cannot, perhaps, justly ascribe any large portion of the general discovery to him: indeed, the conception of the mechanism of the skeleton and muscles was probably so gradually unfolded in the minds of anatomical students, that it would be difficult, even if we knew the labors of each person, to select one, as peculiarly the author of the discovery. But it is clear that all those who did materially contribute to the establishment of this doctrine, must have possessed the qualifications which we find in Galen for such a task; namely, clear mechanical views of what the {442} tensions of collections of strings could do, and an exact practical acquaintance with the muscular cordage which exists in the animal frame;--in short, in this as in other instances of real advance in science, there must have been clear ideas and real facts, unity of thought and extent of observation, brought into contact.

Sect. 2.--Recognition of Final Causes in Physiology. Galen.

THERE is one idea which the researches of the physiologist and the anatomist so constantly force upon him, that he cannot help assuming it as one of the guides of his speculations; I mean, the idea of a purpose, or, as it is called in Aristotelian phrase, a final cause, in the arrangements of the animal frame. It is impossible to doubt that the motive nerves run along the limbs, in order that they may convey to the muscles the impulses of the will; and that the muscles are attached to the bones, in order that they may move and support them. This conviction prevails so steadily among anatomists, that even when the use of any part is altogether unknown, it is still taken for granted that it has some use. The developement of this conviction,--of a purpose in the parts of animals,--of a function to which each portion of the organization is subservient,--contributed greatly to the progress of physiology; for it constantly urged men forwards in their researches respecting each organ, till some definite view of its purpose was obtained. The assumption of hypothetical final causes in Physics may have been, as Bacon asserts it to have been, prejudicial to science; but the assumption of unknown final causes in Physiology, has given rise to the science. The two branches of speculation, Physics and Physiology, were equally led, by every new phenomenon, to ask their question, "Why?" But, in the former case, "why" meant "through what cause?" in the latter, "for what end?" And though it may be possible to introduce into physiology the doctrine of efficient causes, such a step can never obliterate the obligations which the science owes to the pervading conception of a purpose contained in all organization.

This conception makes its appearance very early. Indeed, without any special study of our structure, the thought, that we are fearfully and wonderfully made, forces itself upon men, with a mysterious impressiveness, as a suggestion of our Maker. In this bearing, the thought is developed to a considerable extent in the well-known passage in Xenophon's Conversations of Socrates. Nor did it ever lose its hold on sober-minded and instructed men. The Epicureans, indeed, {443} held that the eye was not made for seeing, nor the ear for hearing; and Asclepiades, whom we have already mentioned as an impudent pretender, adopted this wild dogma.[15\17] Such assertions required no labor. "It is easy," says Galen,[16\17] "for people like Asclepiades, when they come to any difficulty, to say that Nature has worked to no purpose." The great anatomist himself pursues his subject in a very different temper. In a well-known passage, he breaks out into an enthusiastic scorn of the folly of the atheistical notions.[17\17] "Try," he says, "if you can imagine a shoe made with half the skill which appears in the skin of the foot." Some one had spoken of a structure of the human body which he would have preferred to that which it now has. "See," Galen exclaims, after pointing out the absurdity of the imaginary scheme, "see what brutishness there is in this wish. But if I were to spend more words on such cattle, reasonable men might blame me for desecrating my work, which I regard as a religious hymn in honor of the Creator."

[Note 15\17: Sprengel, ii. 15.]

[Note 16\17: De Usu Part. v. 5, (on the kidneys.)]

[Note 17\17: De Usu Part. iii. 10.]

Galen was from the first highly esteemed as an anatomist. He was originally of Pergamus; and after receiving the instructions of many medical and philosophical professors, and especially of those of Alexandria, which was then the metropolis of the learned and scientific world, he came to Rome, where his reputation was soon so great as to excite the envy and hatred of the Roman physicians. The emperors Marcus Aurelius and Lucius Verus would have retained him near them; but he preferred pursuing his travels, directed principally by curiosity. When he died, he left behind him numerous works, all of them of great value for the light they throw on the history of anatomy and medicine; and these were for a long period the storehouse of all the most important anatomical knowledge which the world possessed. In the time of intellectual barrenness and servility, among the Arabians and the Europeans of the dark ages, the writings of Galen had almost unquestioned authority;[18\17] and it was only by an uncommon effort of independent thinking that Abdollatif ventured to assert, that even Galen's assertions must give way to the evidence of the senses. In more modern times, when Vesalius, in the sixteenth century, accused Galen of mistakes, he drew upon himself the hostility of the whole body of physicians. Yet the mistakes were such as might have {444} been pointed out and confessed[19\17] without acrimony, if, in times of revolution, mildness and moderation were possible; but an impatience of the superstition of tradition on the part of the innovators, and an alarm of the subversion of all recognized truths on the part of the established teachers, inflame and pervert all such discussions. Vesalius's main charge against Galen is, that his dissections were performed upon animals, and not upon the human body. Galen himself speaks of the dissection of apes as a very familiar employment, and states that he killed them by drowning. The natural difficulties which, in various ages, have prevented the unlimited prosecution of human dissection, operated strongly among the ancients, and it would have been difficult, under such circumstances, to proceed more judiciously than Galen did.

[Note 18\17: Sprengel, ii. 359.]

[Note 19\17: Cuv. Leçons sur l'Hist. des Sc. Nat. p. 25.]

I shall now proceed to the history of the discovery of another and less obvious function, the circulation of the blood, which belongs to modern times.

II. DISCOVERY OF THE CIRCULATION OF THE BLOOD

Sect. 1.--Prelude to the Discovery.

THE blood-vessels, the veins and arteries, are as evident and peculiar in their appearance as the muscles; but their function is by no means so obvious. Hippocrates[20\17] did not discriminate Veins and Arteries; both are called by the same name (φλέβες) and the word from which artery comes (ἀρτηρίη) means, in his works, the windpipe. Aristotle, scanty as was his knowledge of the vessels of the body, has yet the merit of having traced the origin of all the veins to the heart. He expressly contradicts those of his predecessors who had derived the veins from the head;[21\17] and refers to dissection for the proof. If the book On the Breath be genuine (which is doubted), Aristotle was aware of the distinction between veins and arteries. "Every artery," {445} it is there asserted, "is accompanied by a vein; the former are filled only with breath or air."[22\17] But whether or no this passage be Aristotle's, he held opinions equally erroneous; as, that the windpipe conveys air into the heart.[23\17] Galen[24\17] was far from having views respecting the blood-vessels, as sound as those which he entertained concerning the muscles. He held the liver to be the origin of the veins, and the heart of the arteries. He was, however, acquainted with their junctions, or anastomoses. But we find no material advance in the knowledge of this subject, till we overleap the blank of the middle ages, and reach the dawn of modern science.

[Note 20\17: Sprengel, i. 383.]

[Note 21\17: Hist. Animal. iii. 3.]

[Note 22\17: De Spiritu, v. 1078.]

[Note 23\17: Spr. i. 501.]

[Note 24\17: Ib. ii. 152.]

The father of modern anatomy is held to be Mondino,[25\17] who dissected and taught at Bologna in 1315. Some writers have traced in him the rudiments of the doctrine of the circulation of the blood; for he says that the heart transmits blood to the lungs. But it is allowed, that he afterwards destroys the merit of his remark, by repeating the old assertion that the left ventricle ought to contain spirit or air, which it generates from the blood.

[Note 25\17: Encyc. Brit. 692. Anatomy.]

Anatomy was cultivated with great diligence and talent in Italy by Achillini, Carpa, and Messa, and in France by Sylvius and Stephanus (Dubois and Etienne). Yet still these empty assumptions respecting the heart and blood-vessels kept their ground. Vesalius, a native of Brussels, has been termed the founder of human anatomy, and his great work De Humani Corporis Fabricâ is, even yet, a splendid monument of art, as well as science. It is said that his figures were designed by Titian; and if this be not exactly true, says Cuvier,[26\17] they must, at least, be from the pencil of one of the most distinguished pupils of the great painter; for to this day, though we have more finished drawings, we have no designs that are more artist-like. Fallopius, who succeeded Vesalius at Padua, made some additions to the researches of his predecessor; but in his treatise De Principio Venarum, it is clearly seen[27\17] that the circulation of the blood was unknown to him. Eustachius also, whom Cuvier groups with Vesalius and Fallopius, as the three great founders of modern anatomy, wrote a treatise on the vein azygos[28\17] which is a little treatise on comparative anatomy; but the discovery of the functions of the veins came from a different quarter. {446}

[Note 26\17: Leçons sur l'Hist. des Sc. Nat. p. 21.]

[Note 27\17: Cuv. Sc. Nat. p. 32.]

[Note 28\17: Ib. p. 34.]

The unfortunate Servetus, who was burnt at Geneva as a heretic in 1553, is the first person who speaks distinctly of the small circulation, or that which carries the blood from the heart to the lungs, and back again to the heart. His work entitled Christianismi Restitutio was also burnt; and only two copies are known to have escaped the flames. It is in this work that he asserts the doctrine in question, as a collateral argument or illustration of his subject. "The communication between the right and left ventricle of the heart, is made," he says, "not as is commonly believed, through the partition of the heart, but by a remarkable artifice (magno artificio) the blood is carried from the right ventricle by a long circuit through the lungs; is elaborated by the lungs, made yellow, and transfused from the vena arteriosa into the arteria venosa." This truth is, however, mixed with various of the traditional fancies concerning the "vital spirit, which has its origin in the left ventricle." It may be doubted, also, how far Servetus formed his opinion upon conjecture, and on a hypothetical view of the formation of this vital spirit. And we may, perhaps, more justly ascribe the real establishment of the pulmonary circulation as an inductive truth, to Realdus Columbus, a pupil and successor of Vesalius at Padua, who published a work De Re Anatomicâ in 1559, in which he claims this discovery as his own.[29\17]

[Note 29\17: Encyc. Brit.]

Andrew Cæsalpinus, who has already come under our notice as one of the fathers of modern inductive science, both by his metaphysical and his physical speculations, described the pulmonary circulation still more completely in his Quæstiones Peripateticæ, and even seemed to be on the eve of discovering the great circulation; for he remarked the swelling of veins below ligatures, and inferred from it a refluent motion of blood in these vessels.[30\17] But another discovery of structure was needed, to prepare the way for this discovery of function; and this was made by Fabricius of Acquapendente, who succeeded in the grand list of great professors at Padua, and taught there for fifty years.[31\17] Sylvius had discovered the existence of the valves of the veins; but Fabricius remarked that they are all turned towards the heart. Combining this disposition with that of the valves of the heart, and with the absence of valves in the arteries, he might have come to the conclusion[32\17] that the blood moves in a different direction in the arteries and in the veins, and might thus have discovered the circulation: but this glory was reserved for William Harvey: so true {447} is it, observes Cuvier, that we are often on the brink of a discovery without suspecting that we are so;--so true is it, we may add, that a certain succession of time and of persons is generally necessary to familiarize men with one thought, before they can advance to that which is the next in order.

[Note 30\17: Ib.]

[Note 31\17: Cuv. p. 44.]

[Note 32\17: p. 45.]

Sect. 2.--The Discovery of the Circulation made by Harvey.

WILLIAM HARVEY was born in 1578, at Folkestone in Kent.[33\17] He first studied at Cambridge: he afterwards went to Padua, where the celebrity of Fabricius of Acquapendente attracted from all parts those who wished to be instructed in anatomy and physiology. In this city, excited by the discovery of the valves of the veins, which his master had recently made, and reflecting on the direction of the valves which are at the entrance of the veins into the heart, and at the exit of the arteries from it, he conceived the idea of making experiments, in order to determine what is the course of the blood in its vessels. He found that when he tied up veins in various animals, they swelled below the ligature, or in the part furthest from the heart; while arteries, with a like ligature, swelled on the side next the heart. Combining these facts with the direction of the valves, he came to the conclusion that the blood is impelled, by the left side of the heart, in the arteries to the extremities, and thence returns by the veins into the right side of the heart. He showed, too, how this was confirmed by the phenomena of the pulse, and by the results of opening the vessels. He proved, also, that the circulation of the lungs is a continuation of the larger circulation; and thus the whole doctrine of the double circulation was established.

[Note 33\17: Cuv. p. 51.]

Harvey's experiments had been made in 1616 and 1618; it is commonly said that he first promulgated his opinion in 1619; but the manuscript of the lectures, delivered by him as lecturer to the College of Physicians, is extant in the British Museum, and, containing the propositions on which the doctrine is founded, refers them to April, 1616. It was not till 1628 that he published, at Frankfort, his Exercitatio Anatomica de Motu Cordis et Sanguinis; but he there observes that he had for above nine years confirmed and illustrated his opinion in his lectures, by arguments grounded upon ocular demonstrations. {448}

Sect. 3.--Reception of the Discovery.

WITHOUT dwelling long upon the circumstances of the general reception of this doctrine, we may observe that it was, for the most part, readily accepted by his countrymen, but that abroad it had to encounter considerable opposition. Although, as we have seen, his predecessors had approached so near to the discovery, men's minds were by no means as yet prepared to receive it. Several physicians denied the truth of the opinion, among whom the most eminent was Riolan, professor at the Collège de France. Other writers, as usually happens in the case of great discoveries, asserted that the doctrine was ancient, and even that it was known to Hippocrates. Harvey defended his opinion with spirit and temper; yet he appears to have retained a lively recollection of the disagreeable nature of the struggles in which he was thus involved. At a later period of his life, Ent,[34\17] one of his admirers, who visited him, and urged him to publish the researches on generation, on which he had long been engaged, gives this account of the manner in which he received the proposal: "And would you then advise me, (smilingly replies the doctor,) to quit the tranquillity of this haven, wherein I now calmly spend my days, and again commit myself to the unfaithful ocean? You are not ignorant how great troubles my lucubrations, formerly published, have raised. Better it is, certainly, at some time, to endeavor to grow wise at home in private, than by the hasty divulgation of such things to the knowledge whereof you have attained with vast labor, to stir up tempests that may deprive you of your leisure and quiet for the future."

[Note 34\17: Epist. Dedic. to Anatom. Exercit.]

His merits were, however, soon generally recognized. He was[35\17] made physician to James the First, and afterwards to Charles the First, and attended that unfortunate monarch in the civil war. He had the permission of the parliament to accompany the king on his leaving London; but this did not protect him from having his house plundered in his absence, not only of its furniture, but, which he felt more, of the records of his experiments. In 1652, his brethren of the College of Physicians placed a marble bust of him in their hall, with an inscription recording his discoveries; and two years later, he was nominated to the office of President of the College, which however he {449} declined in consequence of his age and infirmities. His doctrine soon acquired popular currency; it was, for instance, taken by Descartes[36\17] as the basis of his physiology in his work On Man; and Harvey had the pleasure, which is often denied to discoverers, of seeing his discovery generally adopted during his lifetime.

[Note 35\17: Biog. Brit.]

[Note 36\17: Cuv. 53.]

Sect. 4.--Bearing of the Discovery on the Progress of Physiology.

IN considering the intellectual processes by which Harvey's discoveries were made, it is impossible not to notice, that the recognition of a creative purpose, which, as we have said, appears in all sound physiological reasonings, prevails eminently here. "I remember," says Boyle, "that when I asked our famous Harvey what were the things that induced him to think of a circulation of the blood, he answered me, that when he took notice that the valves in the veins of so many parts of the body were so placed, that they gave a free passage to the blood towards the heart, but opposed the passage of the venal blood the contrary way; he was incited to imagine that so provident a cause as Nature had not placed so many valves without design; and no design seemed more probable than that the blood should be sent through the arteries, and return through the veins, whose valves did not oppose its course that way."

We may notice further, that this discovery implied the usual conditions, distinct general notions, careful observation of many facts, and the mental act of bringing together these elements of truth. Harvey must have possessed clear views of the motions and pressures of a fluid circulating in ramifying tubes, to enable him to see how the position of valves, the pulsation of the heart, the effects of ligatures, of bleeding, and of other circumstances, ought to manifest themselves in order to confirm his view. That he referred to a multiplied and varied experience for the evidence that it was so confirmed, we have already said. Like all the best philosophers of his time, he insists rigidly upon the necessity of such experience. "In every science," he says,[37\17] "be it what it will, a diligent observation is requisite, and sense itself must be frequently consulted. We must not rely upon other men's experience, but our own, without which no man is a proper disciple of any part of natural knowledge." And by publishing his experiments, he trusts, he adds, that he has enabled his reader "to be an equitable {450} umpire between Aristotle and Galen;" or rather, he might have said, to see how, in the promotion of science, sense and reason, observation and invention, have a mutual need of each other.

[Note 37\17: Generation of Animals, Pref.]

We may observe further, that though Harvey's glory, in the case now before us, rested upon his having proved the reality of certain mechanical movements and actions in the blood, this discovery, and all other physiological truths, necessarily involved the assumption of some peculiar agency belonging to living things, different both from mechanical agency, and from chemical; and in short, something vital, and not physical merely. For when it was seen that the pulsation of the heart, its systole and diastole, caused the circulation of the blood, it might still be asked, what force caused this constantly-recurring contraction and expansion. And again, circulation is closely connected with respiration; the blood is, by the circulation, carried to the lungs, and is there, according to the expression of Columbus and Harvey, mixed with air. But by what mechanism does this mixture take place, and what is the real nature of it? And when succeeding researches had enabled physiologists to give an answer to this question, as far as chemical relations go, and to say, that the change consists in the abstraction of the carbon from the blood by means of the oxygen of the atmosphere; they were still only led to ask further, how this chemical change was effected, and how such a change of the blood fitted it for its uses. Every function of which we explain the course, the mechanism, or the chemistry, is connected with other functions,--is subservient to them, and they to it; and all together are parts of the general vital system of the animal, ministering to its life, but deriving their activity from the life. Life is not a collection of forces, or polarities, or affinities, such as any of the physical or chemical sciences contemplate; it has powers of its own, which often supersede those subordinate relations; and in the cases where men have traced such agents in the animal frame, they have always seen, and usually acknowledged, that these agents were ministerial to some higher agency, more difficult to trace than these, but more truly the cause of the phenomena.

The discovery of the mechanical and chemical conditions of the vital functions, as a step in physiology, may be compared to the discovery of the laws of phenomena in the heavens by Kepler and his predecessors, while the discovery of the force by which they were produced was still reserved in mystery for Newton to bring to light. The subordinate relation of the facts, their **dependence on space and time, their reduction to order and cycle, had been fully performed; but the {451} reference of them to distinct ideas of causation, their interpretation as the results of mechanical force, was omitted or attempted in vain. The very notion of such Force, and of the manner in which motions were determined by it, was in the highest degree vague and vacillating; and a century was requisite, as we have seen, to give to the notion that clearness and fixity which made the Mechanics of the Heavens a possible science. In like manner, the notion of Life, and of Vital Forces, is still too obscure to be steadily held. We cannot connect it distinctly with severe inductions from facts. We can trace the motions of the animal fluids as Kepler traced the motions of the planets; but when we seek to render a reason for these motions, like him, we recur to terms of a wide and profound, but mysterious import; to Virtues, Influences, undefined Powers. Yet we are not on this account to despair. The very instance to which I am referring shows us how rich is the promise of the future. Why, says Cuvier,[38\17] may not Natural History one day have its Newton? The idea of the vital forces may gradually become so clear and definite as to be available in science; and future generations may include, in their physiology, propositions elevated as far above the circulation of the blood, as the doctrine of universal gravitation goes beyond the explanation of the heavenly motions by epicycles.

[Note 38\17: Ossem. Foss. Introd.]

If, by what has been said, I have exemplified sufficiently the nature of those steps in physiology, which, like the discovery of the Circulation, give an explanation of the process of some of the animal functions, it is not necessary for me to dwell longer on the subject; for to write a history, or even a sketch of the history of Physiology, would suit neither my powers nor my purpose. Some further analysis of the general views which have been promulgated by the most eminent physiologists, may perhaps be attempted in treating of the Philosophy of Inductive Science; but the estimation of the value of recent speculations and investigations must be left to those who have made this vast subject the study of their lives. A few brief notices may, however, be here introduced. {452}

Chapter III

DISCOVERY OF THE MOTION OF THE CHYLE, AND CONSEQUENT SPECULATIONS.

Sect. 1.--The Discovery of the Motion of the Chyle.

IT may have been observed in the previous course of this History of the Sciences, that the discoveries in each science have a peculiar physiognomy: something of a common type may be traced in the progress of each of the theories belonging to the same department of knowledge. We may notice something of this common form in the various branches of physiological speculation. In most, or all of them, we have, as we have noticed the case to be with respect to the circulation of the blood, clear and certain discoveries of mechanical and chemical processes, succeeded by speculations far more obscure, doubtful, and vague, respecting the relation of these changes to the laws of life. This feature in the history of physiology may be further instanced, (it shall be done very briefly), in one or two other cases. And we may observe, that the lesson which we are to collect from this narrative, is by no means that we are to confine ourselves to the positive discovery, and reject all the less clear and certain speculations. To do this, would be to lose most of the chances of ulterior progress; for though it may be, that our conceptions of the nature of organic life are not yet sufficiently precise and steady to become the guides to positive inductive truths, still the only way in which these peculiar physiological ideas can be made more distinct and precise, and thus brought more nearly into a scientific form, is by this struggle with our ignorance or imperfect knowledge. This is the lesson we have learnt from the history of physical astronomy and other sciences. We must strive to refer facts which are known and understood, to higher principles, of which we cannot doubt the existence, and of which, in some degree, we can see the place; however dim and shadowy may be the glimpses we have hitherto been able to obtain of their forms. We may often fail in such attempts, but without the attempt we can never succeed. {453}

That the food is received into the stomach, there undergoes a change of its consistence, and is then propelled along the intestines, are obvious facts in the animal economy. But a discovery made in the course of the seventeenth century brought into clearer light the sequel of this series of processes, and its connexion with other functions. In the year 1622, Asellius or Aselli[39\17] discovered certain minute vessels, termed lacteals, which absorb a white liquid (the chyle) from the bowels, and pour it into the blood. These vessels had, in fact, been discovered by Eristratus, in the ancient world,[40\17] in the time of Ptolemy; but Aselli was the first modern who attended to them. He described them in a treatise entitled De Venis Lacteis, cum figuris elegantissimis, printed at Milan in 1627, the year after the death of the author. The work is remarkable as the first which exhibits colored anatomical figures; the arteries and veins are represented in red, the lacteals in black.

[Note 39\17: Mayo, Physiology, p. 156.]

[Note 40\17: Cuv. Hist. Sc. p. 50.]

Eustachius,[41\17] at an earlier period, had described (in the horse) the thoracic duct by which the chyle is poured into the subclavian vein, on the right side of the neck. But this description did not excite so much notice as to prevent its being forgotten, and rediscovered in 1550, after the knowledge of the circulation of the blood had given more importance to such a discovery. Up to this time,[42\17] it had been supposed that the lacteals carried the chyle to the liver, and that the blood was manufactured there. This opinion had prevailed in all the works of the ancients and moderns; its falsity was discovered by Pecquet, a French physician, and published in 1651, in his New Anatomical Experiments; in which are discovered a receptacle of the chyle, unknown till then, and the vessel which conveys it to the subclavian vein. Pecquet himself and other anatomists, soon connected this discovery with the doctrine, then recently promulgated, of the circulation of the blood. In 1665, these vessels, and the lymphatics which are connected with them, were further illustrated by Ruysch in his exhibition of their valves. (Dilucidatio valvularum in vasis lymphaticis et lacteis.)

[Note 41\17: Cuv. Hist. p. 34.]

[Note 42\17: Ib. p. 365.]

Sect. 2.--The Consequent Speculations. Hypotheses of Digestion.

THUS it was shown that aliments taken into the stomach are, by its action, made to produce chyme; from the chyme, gradually changed {454} in its progress through the intestines, chyle is absorbed by the lacteals; and this, poured into the blood by the thoracic duct, repairs the waste and nourishes the growth of the animal. But by what powers is the food made to undergo these transformations? Can we explain them on mechanical or on chemical principles? Here we come to a part of physiology less certain than the discovery of vessels, or of the motion of fluids. We have a number of opinions on this subject, but no universally acknowledged truth. We have a collection of Hypotheses of Digestion and Nutrition.

I shall confine myself to the former class; and without dwelling long upon these, I shall mention some of them. The philosophers of the Academy del Cimento, and several others, having experimented on the stomach of gallinaceous birds, and observed the astonishing force with which it breaks and grinds substances, were led to consider the digestion which takes place in the stomach as a kind of trituration.[43\17] Other writers thought it was more properly described as fermentation; others again spoke of it as a putrefaction. Varignon gave a merely physical account of the first part of the process, maintaining that the division of the aliments was the effect of the disengagement of the air introduced into the stomach, and dilated by the heat of the body. The opinion that digestion is a solution of the food by the gastric juice has been more extensively entertained.

[Note 43\17: Bourdon, Physiol. Comp. p. 514.]

Spallanzani and others made many experiments on this subject. Yet it is denied by the best physiologists, that the changes of digestion can be adequately represented as chemical changes only. The nerves of the stomach (the pneumo-gastric) are said to be essential to digestion. Dr. Wilson Philip has asserted that the influence of these nerves, when they are destroyed, may be replaced by a galvanic current.[44\17] This might give rise to a supposition that digestion depends on galvanism. Yet we cannot doubt that all these hypotheses,--mechanical, physical, chemical, galvanic--are altogether insufficient. "The stomach must have," as Dr. Prout says,[45\17] "the power of {455} organizing and vitalizing the different elementary substances. It is impossible to imagine that this organizing agency of the stomach can be chemical. This agency is vital, and its nature completely unknown."

[Note 44\17: Müller (Manual of Physiology, B. iii. Sect. 1, Chap. iii.) speaks of Dr. Wilson Philip's assertion that the nerves of the stomach being cut, and a galvanic current kept up in them, digestion is still accomplished. He states that he and other physiologists have repeated such experiments on an extensive scale, and have found no effect of this kind.]

[Note 45\17: Bridgewater Tr. p. 493.]