productive of no greater inconvenience to those that remain, than the swarming of bees is to their parent hive.

It is obvious therefore that they in reality bear a close analogy to corals and polypes; and this leads us to the inquiry as to how plants differ from the animal kingdom. If animals consisted only of quadrupeds, and birds, and fishes, and vegetables were confined to trees and herbs, no conceivable difficulty of assigning to each kingdom the most positive limits could be experienced. For every person sees how wide a difference exists between the larger animals and the more conspicuous plants: the less indeed we are acquainted with the subject, the more easy is the task of distinguishing them; but to those who are acquainted with the infinite varieties of form, structure, and nature, which are included within these kingdoms, the limits which divide them will be found to present one of the most difficult problems in the philosophy of natural history.

continually rooted to the same spot, which have no power of roaming from place to place in search of aliment, which have no capability of distinguishing between the useful and the hurtful, the wholesome and the poisonous, but which are compelled to derive their support from such matter as chance may place immediately and continually in contact with them, and which therefore experience no cessation to the supply of food, are not provided by nature with organs of mastication. The want of these organs renders a stomach unnecessary; internal absorption or intussusception of nutriment cannot take place; and we accordingly find that their existence is sustained not by an uncertain periodical introduction of food into an internal cavity, but by the perpetual absorption of food from the matter perpetually about them, through pores of their surface too fine for human perception. Nothing therefore which requires to be divided by mechanical force, nothing which needs to be altered in its texture or substance before it can be used, or to be digested, nothing which has to be sought for, nothing in short but matter which is so delicate as to pass through perforations, which the human senses, aided by the most powerful microscopes cannot distinguish, is fitted for the support of plants; and no inorganic matter exists which answers to this description, but water or air, or substances held in solution by these two elements, and such in fact are the materials by which vegetables are supported.

As an ingenious French physiologist has well remarked, it is not a question about what are the characters peculiar to animals, but what are common to them all. We know very well that they only have brain, nerves, muscles, a heart, lungs, a stomach, and a skeleton; that they move, digest, respire; that they have blood, and appear to have sensation; but what remains of all these characters when we descend the long chain that they form, from the first link to the last. Almost nothing. Lungs, glands, brain, skeleton, heart, arteries, blood, nerves, and muscles, successively disappear, till at last we are not sure whether we have even a stomach left. (Isid. Bourdon, Phys. compar. p. 10.) If a comparison is instituted between the highest form of development in either kingdom, between a human being and a tree, the differences are too striking to escape the most ordinary observation. We see that animals are endued with sensation or perception; that they possess locomotivity, or the power of transporting themselves from place to place; that they live upon organic substances which their powers of locomotion and perception enable them to select; that their food passes through an alimentary cavity, from which its nutritive properties are transfused by means of absorbent vessels into the system. Plants, on the contrary, are destitute of all traces of a nervous system and conse-said, that animals die of old age or accidents, vegetables of quently of perception; they are fixed to a particular spot whence nothing but mechanical power can remove them; they are incapable of all motion, except from some internal mechanical agency; they subsist upon such inorganic matter as surrounds them, and their food is at once introduced into their system by absorption through their external surface only.

Vegetables are also said to be compound beings, animals simple beings. For illustration, whatever objections may be taken to such a comparison, the latter may be considered, with Link and Blumenbach, to have only one seat of life, the sensorium commune, and to have but one provision made by nature for their propagation; the former, which are capable of reproduction by various means from various points of their body, must have the seats of vitality as numerous as the parts which are thus capable of self-perpetuation. Hence articulations, buds either latent or developed, and seeds, are in plants so many distinct seats of vegetable life. While all-powerful man has but one feeble means granted him of perpetuating his race, millions of millions of individuals, which in a physiological sense are identically the same, have been produced by the half-dozen potatoes brought to Europe by Raleigh, in 1584, and this without any aid from the ordinary means which nature has given plants for their multiplication.

Among the distinctions between the animal and vegetable kingdom, that which demands the first consideration is the different means possessed by animals and vegetables of procuring food and of imbibing nourishment. Animals have the power of moving from place to place, and are gifted with perception, which enables them to distinguish what is proper for their sustenance. They are also furnished with organs of mastication, which enable them to reduce to minute pieces very hard substances. As their food is only procured by an act of exertion on the part of the animal, and as this exertion is not continual and uninterrupted, but only takes place at intervals of time, they are also provided with an internal reservoir in which the food that is so procured is deposited; from this reservoir, called the stomach, the absorbent vessels conduct the elaborable parts into the system, while the solid useless parts are rejected: animals therefore are nourished by internal absorption. Vegetables which are

As in animals, nourishment is derived from their centre, so it follows that all their absorbent vessels have a direction towards that centre; and for the same reason, as in plants, nutrition is communicated from the outside, so is it in that direction that all the absorbent vessels of the vegetable are directed. The consequence of these two laws is, that while a term is prescribed to the growth of the most perfect animals, no limit seems to be fixed for that of the most perfect vegetables. The former perish as soon as their original vessels become incapable of performing their functions; the latter endure until the power of forming new vessels shall cease. The period to the former is fixed, to the latter unlimited. Hence an eloquent French writer has ingeniously accidents alone. Hence also the incredible age to which certain trees arrive. The cedars of Mount Lebanon are said to be of an antiquity far beyond all history; and it has been calculated by a French botanist, from actual inspection, that the age of the baobab trees of Senegal must have exceeded 6000 years. These are the most decided differences between animal and vegetable life, and are almost without exception. Some plants, indeed, having only an annual or biennial existence, have a term fixed to their lives, just as animals have, but no plants can be pointed out in which nourishment does not take place from the outside. When we descend in the scale of being, when we arrive at those limits of the world where life first arises out of death, in which sensation is indistinguishable, and from which the two kingdoms seem to diverge as from a common point, even there we find the polypes, which are so simple in their structure that they may be turned inside out like a glove, always conforming to this law. Zoologists assure us that they still absorb from the inside even when that part of the body which was once the outside has to perform the duties of a stomach.

But with this exception we know of no absolute external distinction which has yet been discovered between animals and vegetables. The ingenious idea of Mirbel, that animals live upon organic, vegetables upon inorganic matter, must, as respects the infusorial animalculæ, be a purely hypothetical difference, and in more perfect animals is not true, as has been shown by Mr. William MacLeay, who asserts that many animals of the lower tribes, and some Heteromerous Coleoptera, have been observed to feed upon inorganic matter.' (Hora Entomologicæ, ii. 193.)

If we now reconsider the observations which have just been made, and endeavour to see to what the distinction of animals and vegetables is really reducible, we shall find that it consists in animals being organic beings, possessed of sensation and locomotion, and sustained by the absorption of nutriment through an internal canal, while plants have no sensation or locomotion, and are nourished by absorption through their cuticle. But how are we to apply these distinctions to the lower orders of created beings? Among these we find productions, which it is impossible, by the characters now assigned, to refer with any exactness either

to the one kingdom or the other. A drop of water and a little brown or green slime from a ditch will often afford abundant evidence of the accuracy of this remark.

To which kingdom are we to refer the beautiful Salmacis and all the tribe by some botanists called Confervæ conjugata, or Zygnemas, which Messrs. Gaillon and De If we place a drop of water and a few fragments of con- Blainville assert to be of animal nature, but which grow fervæ under a microscope, we shall probably discover an like vegetables, from which they are undistinguishable by abundance of little bodies shaped like a weaver's shuttle, external characters. They are transparent tubes, having transparent at the extremities and in the middle, with two distinct articulations and transverse partitions, the cavity or four semi-opaque brownish cavities in their inside: these being filled with brilliant green spherules arranged with the bodies have a sort of starting motion, very distinct and con- most beautiful symmetry in one or more spires, which, tinued, but they do not seem capable of turning on either separating at a certain period of their existence, and passing axis; nor is any motion of contraction visible; they vary in through the sides of the tube, develop in the form of new length, according to De Blainville (Dict. des Sc. Nat. 34, 367), tubes exactly like their parent. When in a perfect state from the five-hundredth to the hundredth of a line, and the contiguous tubes or filaments unite in a manner comwhen full grown exceed these dimensions considerably. By pletely animal in appearance, uniting at one period, sepaMüller, a standard writer upon infusorial animalcules, they rating at another, and finally combining themselves into are considered animals, and referred to his genus Vibrio, a single and uniform being. part of which consists of bodies of an undoubted animal nature. By modern observers they have been named Navicula. When young they are attached to conferva by a stalk so delicate as to be almost invisible with the aid of the most perfect microscopes, and during this period they have, according to M. Bory de St. Vincent, no visible motion whatever; but when the Navicula is fully formed it separates from the plant on which it grew, swimming and starting about in the water in the way described. Are such productions animal or vegetable? When young they are motionless and vegetable like a minute plant; when full grown they acquire the movement of animals. Perhaps one may say they are the latter, and compare their vegetating state when young to that of the Polype, called Vorticella, an undoubted animal, if rapid and varied motion can make it so. Among confervæ in ditches are often found little fragments of organized bodies; some like ribbands, separable completely into numberless narrow transverse portions, others dividing partially at their articulations, but adhering at their angles like chains of square transparent cases. These enter the genera called by naturalists Diatoma, Fragilaria, Exilaria, Achnanthes. Are they animals or plants? When combined they are motionless, with all the appearance of confervæ, their transparent joints filled with the green reproductive matter of such plants; but when they disarticulate, their separate portions have a distinct sliding or starting motion. Shall we call them, with M. Gaillon, chains of animals assembled in a voluntary captivity which no one has seen them assume; or shall we not be rather justified in viewing them as links between the animal and vegetable kingdoms, and endowed with the characters of both.

Conferva mutabilis, or Draparnaldia, is a plant-like body, which, according to Messrs. Mertens and Gaillon, is sometimes an animal, sometimes a plant. The former says that he has frequently seen it undergo its transformation, particularly in August, 1822. On the 3rd of that month he showed it to a great number of persons in a state of plant; on the 5th it had disarticulated into portions distinctly moving in water, which on the 6th began again to unite, and on the 10th became finally combined into their primitive state of conferva. (Dict. des Sc. Nat., 34, 373.)

It perhaps may be said that the instances yet given are not at variance with the distinction of animals and vegetables by their power of motion; and that as they are all inert when in their most perfect state, their giving birth to moving bodies does not make them animals any more than the production of motionless eggs by birds, reptiles, and mollusca makes them vegetables.

In which kingdom then are we to station the curious Polyphysa, a most undoubted polyp, according to Lamouroux, Leman, and De Blainville; an equally certain plant if we are to believe Turner, Agardh, and Gaudichaud, the last of whom found it living, and describes it thus. It grows in thick tufts to the shells which are thrown ashore upon the barren coast of Shark's Bay in New Holland. Each individual consists of a fistular, capillary, greenish stalk, about an inch or an inch and a half long, expanding at the base into a sort of root-like claw, by which it is fixed. At the end it bears from fifteen to eighteen sacs, which are entire, rounded at the end, and slightly attenuated to the base; each contains a multitude of little round green globules, which finally expand and break through the thin case in which they are included. They are filled with a green unctuous matter, and the colour of the parent body is entirely due to their presence, for when they have all escaped from their sacs, the mother body is perfectly colourless.

Lastly, where are we to place the oscillating confervæ, those slime-like masses which cover the earth in damp and shady places, or form mucous patches among the confervæ and polypes of stagnant water, or appear under the form of a rich carmine stain, bordered with resplendent violet and blue, on the surface of hot springs, in all parts of the world; productions which, according to the speculations of an inge nious Swedish naturalist, have once possessed an animal life, of which they now only retain the appearance. These oscillatorias consist of articulated tubes filled with green granules, and grow and increase like confervæ, and the reproductive particles to which they give birth have no motion that is apparent. But the tubes themselves have a writhing, twisting, undulating, creeping, distinctly animal motion, which it is impossible to mistake; they are more active in warm than in cold weather, and in the latter can be excited to action by the application of warmth. When chemically examined, they have been found to exhibit many of the characters peculiar to the animal kingdom; and when burnt, yield a carbon of the most fetid odour, exactly resembling that of decaying animal substances.

Such are a few of the difficulties which that naturalist has to overcome who would fix the limits between the animal and vegetable kingdoms. It is clear that the power of voluntary motion exists in beings having a distinctly vegetable structure, both in the most perfect state and in a state of disintegration; that the absorption of nutriment from the inside in the one family, and from the outside in the other, is a character not appreciable in such creatures as the monads, and the vivifying animalcules of flowering plants; and, finally, that chemical differences are destroyed by anabaina and oscillatorias. In this difficulty shall we admit, with M. Bory de St. Vincent, a new kingdom intermediate between animals and plants, characterized as consisting of insensible individuals, that develop and increase in the manner of vegetables, up to the period when they separate into animated germs or reproductive fragments; or shall not we rather consider the absence of all exact limits between animal and vegetable nature as a striking proof of the beautiful harmony of nature, and of that unity of purpose which is so visible in all the works of the Creator; as an evidence that all the forms of life are but assemblages in insensible gradation of the same living matter differently combined by the great Spirit that pervades all matter and all space?

II. In treating of the history of this science, we have no intention of entering upon details which can only interest the systematical botanist, or of criticising every step which its followers may have taken; but, on the contrary, we shall confine ourselves to a mere sketch of the progress that has been made in elucidating the great principles by which its rank as a branch of philosophy is to be determined.

It is obvious from various passages in the most antient writers, that the art of distinguishing certain plants having medical virtues was taught at the earliest period of which we have any written record; and that the cultivation of something more than corn was already understood in the Homeric days is sufficiently attested by the references to the vineyards of Laertes and the gardens of Alcinous, and by the employment assigned to Lycaon, the son of Priam, of pruning figs in his father's garden.

The earliest tangible evidence that we possess of the real state of knowledge upon this subject is afforded by the remains of the writings of Aristotle and his school. From the absurd superstitions of the root-cutters (rhizotomi) of this period it might be imagined that at this time botany was far from having any real existence; for it is to them that we

have to trace the belief in the necessity of magical ceremonies | precise for the words of a poet; and although to these and personal purification or preparation in collecting herbs; operations were attributed powers which they did not possome sorts, they tell us, are to be cut against the wind, others sess, yet it is abundantly plain that the processes were after the body of the rhizotomist has been well oiled, some at thoroughly understood. The night, some by day. Alliaceous food was a necessary preparation for procuring this herb, a draught of wine for that, and so on. But in fact at this very time the Peripatetic philosophers were in possession of a considerable mass of correct information concerning the nature of vegetable life, mixed up indeed with much that was fanciful and hypothetical, but calculated to give us a high opinion of their acuteness and of the amount of positive knowledge upon such subjects which had by that time been collected. It is by this school that botany must be considered to have been first formed into a science. Aristotle, in all probability, was its founder; for it is obvious from the remarks upon plants scattered through his books concerning animals, that his knowledge of vegetable physiology was, for his day, of a most remarkable kind. But as the books immediately concerning plants ascribed to this philosopher are undoubted forgeries, it will be more convenient to take the works of Theophrastus as our principal guide to a determination of the state of botany at the commencement of this

having comprehended several combinations which are re-subsequently required correction. From him physiological cognized at the present day: Cucurbitaceæ, Stellatæ, Gra- botany, properly speaking, took its origin. Clear and dismineæ, Labiata, Boragineæ, Leguminosa, Filices, were all tinct ideas of the true causes of vegetable phenomena gradistinctly indicated; and it may be added that under the dually arose out of a consideration of the physical properties name of Asphodels he grouped the principal part of modern of the minute parts through whose combined action they are petaloid monocotyledons. The reasons however why such brought about; and a solid foundation was laid for the groups were constituted were not then susceptible of defini- theories of vegetation which subsequent botanists have protion; the true principles of classification had to be elicited by pounded: to Grew may also be ascribed the honour of having the long and patient study of succeeding ages. Among first pointed out the important difference between seeds the foremost to take up this important subject was Casal with one cotyledon, and those with two, and of having thus pinus, a Roman physician attached to the court of Pope been the discoverer of the two great natural classes into Sixtus V. This naturalist possessed a degree of insight which the flowering part of the vegetable kingdom is now into the science far beyond that of his age, and is memo- divided. Grew, however, was no systematist; it was rerable for the justness with which he appreciated many of the served for another Englishman to discover the true prinless obvious circumstances which his predecessors had over- ciples of classification, and thus to commence looked. For example, he was aware of the circulation of the sap; he believed that its ascent from the roots was caused by heat; he knew that leaves are cortical expansions traversed by veins, proceeding in part from the liber; he estimated the pith of plants at its true value, and seeds he compared to eggs, in which there exists a vital principle | without life; but he denied the existence of sexes in the vegetable kingdom. Improving upon the views of Gesner, he showed how great is the value of the fructification in systematic botany; the flower he said was nothing but the wrapper of the fruit; the essential part of the seed he considered to be what is called the corculum, that is the double cone of plumule and radicle which connects the cotyledons. In general his views of vegetable physiology were much more just than those of his predecessors, and if he did not avoid the error of supposing certain plants to be mere abortions of more perfect species, as many grasses of corn, he amply redeemed his fame by the correction of other mistakes. From differences in the fruit and the seed of plants, he formed a system which, though purely artificial, and never much employed, had the merit of calling attention strongly to the existence of a class of important characters which had previously been either overlooked or undervalued. But notwithstanding the attempts thus made by a few distinguished men to elevate the science to a higher station, and to reduce it to some general principles, it still continued to languish and to remain for the most part in the hands of the most ignorant pretenders, and in no country more so than in England. We find, upon the authority of the celebrated Ray, that in this country in the middle of the seventeenth century it was in the most lamentable state. At that time the standard book of English botanists was a publication called Gerarde's 'Herbal, which was, as Ray tells us, the production of a man almost entirely ignorant of the learned languages, in which nevertheless all books on science were at that time written. The principal part of the work was pirated from the 'Pemptades' of Dodoens, turned into English by one Priest, and, in order to conceal the plunder, the arrangement of Dodoens was exchanged for that of Lobel, while the whole was made up with the wood-blocks of Tabernæmontanus' Kräuterbuch, often unskilfully transposed and confounded. At last a change, as sudden as it was important, was produced in the science by the application of the microscope to botanical purposes.

The Third Era.-About the middle of the seventeenth century this instrument was first employed in the examination of the elementary organs of plants, about which nothing had been previously learned since the time of Theophrastus. The discovery of spiral vessels by Henshaw in 1661, the examination of the cellular tissue by Hook at a somewhat later date, at once excited the attention of observers, and led at nearly the same time to the appearance of two works upon vegetable anatomy, which at once so nearly exhausted the subject, that it can scarcely be said to have again advanced till the beginning of the present century. Grew and Malpighi, the writers thus adverted to, but more especially the former, combined with rare powers of observation a degree of patience which few men have ever possessed. They each examined the anatomy of vegetation in its minutest details, the former principally in the abstract, the latter more comparatively with the animal kingdom. Various forms of cellular tissue, inter-cellular passages, spiral vessels, woody tubes, ducts, the nature of hairs, the true structure of wood, were made at once familiar to the botanist; the real nature of sexes in plants was demonstrated; and it is quite surprising to look back on those days from the present high ground on which botany has taken its stand, and to see how little the views of Grew at least have

The Fourth Era.-John Ray, a man of a capacious mind, of singular powers of observation, and of extensive learning, driven from his collegiate employments by the infamous commands of a profligate prince, sought consolation in the study of natural history, to which he had been attached from his youth. Botany he found was fast settling back into the chaos of the middle ages, partly beneath the weight of undigested materials, but more from the want of some fixed principles by which the knowledge of the day should be methodized. Profiting by the discoveries of Grew and the other vegetable anatomists, to which he added a great store of original observation, he in his 'Historia Plantarum,' the first volume of which appeared in 1686, embodied in one connected series all the facts that had been collected concerning the structure and functions of plants: to these he added an exposition of what he considered the philosophy of classification, as indicated partly by human reason, and partly by experience; and from the whole he deduced a classification which is unquestionably the basis of that which, under the name of the system of Jussieu, is every where recognized at the present day. For proofs of this, we refer our readers to the memoir of Ray in the present work: we will only observe in this place that he separated flowering from flowerless plants; that he divided the former into monocotyledons and dicotyledons, and that under these three heads he arranged a considerable number of groups, partly his own, partly taken from Lobel and others; which are substantially the same as what are received by botanists of the present day under the name of natural orders. It is singular enough that the merits of this arrangement of John Ray should have been so little appreciated by his contemporaries and immediate successors, as to have been but little adopted; and that, instead of endeavouring to correct its errors and to remove its imperfections, botanists occupied themselves for several succeeding years in attempts at discovering other systems, the greater part of which were abandoned almost as soon as they were made known. Rivinus, Magnol, Tournefort, and Linnæus were the most celebrated of these writers; but the two last alone have had any permanent reputation. Tournefort, who for a long time stood at the head of the French school of botany, proposed, in 1694, a method of arrangement, in its principles entirely artificial, but which in some cases was accidentally in accordance with natural affinities. It was founded chiefly upon differences in the corolla, without the slightest reference to physiological peculiarities; and is now forgotten, except in consequence of its having furnished some useful ideas to Jussieu, as will be hereafter shown.

The Fifth Era-Linnæus was a genius of a different and a higher order. Educated in the severe school of adversity, accustomed from his earliest youth to estimate higher than all other things verbal accuracy and a logical precision, which are often most seductive when least applicable; endowed by nature with a most brilliant understanding, and capable, from constitutional strength, of any fatigue either of mind or body, this extraordinary man was destined to produce a revolution in botany, among other branches of natural history, which in some respects advanced and in others retarded its progress far more than the acts of any one who had preceded him. He found the phraseology bad, and he improved it; the nomenclature was awkward and inconvenient, he simplified it; the distinctions of genera and species, however much the former had been improved by Tournefort, were vague and too often empirical; he defined them with an apparent rigour, which the world thought admirable, but which Nature spurned; he found the classifications of his day so vague and uncertain, that no two persons were agreed as to their value, and for them he substituted a

scheme of the most specious aspect, in which all things superficial botanists; of men who supposed that nomenseemed as clearly circumscribed by rule and line as the clature and verbal criticism constitute the whole objects of fields in the map of an estate; he fancied he had gained the science; who have been distinguished more for their the mastery over nature, that he had discovered a mighty total neglect of everything beyond mere technicalities, than spell that would bind her down to be dissected and anato- the old botanists for their disregard of the latter; who have mized, and the world believed him; in short, he seized upon had no general views, and apparently no power of applying all the wardrobe of creation, and his followers never doubted their means to any intelligible end, and who, consequently, that the bodiless puppets which he set in action were really in the countries where they have flourished, have so far the divine soul and essence of the organic world. Such was lessened the science in public estimation, and done as much Linnaeus; the mighty spirit of his day. Let us do this great to retard its progress as Linnæus did to advance it. man that justice which exaggeration on the one hand, and The maxims however of Ray, and the great general views detraction on the other, have too often refused to him; and of that illustrious naturalist, were destined not to fade even let us view his character soberly and without prejudice. We before the meteoric brilliancy that surrounded the throne of shall then admit that no naturalist has ever been his supe- Linnæus. A French botanist, Antoine Laurent de Jussieu, rior; and that he richly merited that high station in science soon entered the field to oppose the latter. In the year 1789, which he held for so many years. His verbal accuracy, just eleven years after the death of Linnæus, he produced, upon which his fame greatly depends, together with the re- under the name of 'Genera Plantarum,' an arrangement markable terseness of his technical language, reduced the of plants according to their natural relations, in which crude matter that was stored up in the folios of his predeces- the principles of the great English botanist are tacitly adsors into a form that was accessible to all men. He sepa- mitted, and his fundamental divisions adopted in combirated with singular skill the important from the unimportant nation in part with those of Tournefort, and in part with what in their descriptions. He arrayed their endless synonyms are peculiar to the author himself. Jussieu possessed in a with a patience and lucid order that were quite inimitable. happier degree than any man that has succeeded him the By requiring all species to be capable of a rigorous defini- art of adapting the simplicity and accuracy of the language tion not exceeding twelve words, he purified botany of the of Linnæus to the exigencies of science, without encumberendless varieties of the gardeners and herbalists; by applying himself with its pedantry. He knew the impossibility ing the same strict principles to genera, and reducing every of employing any single characters to distinguish objects character to its differential terms, he got rid of all the cum- so variable in their nature as plants; and he clearly saw to brous descriptions of the old writers. Finally, by the inven- what evils all artificial systems must of necessity give rise. tion of an artificial system, every division of which was de- Without pretending then to the conciseness of Linnæus in fined in the most rigorous manner, he was able so to classify forming his generic characters, he rendered them as brief as all the materials thus purified and simplified, that it seemed was consistent with clearness; without peremptorily excludas if every one could become a botanist without more pre- ing all distinctions not derived from the fructification, vious study than would be required to learn how to discover he nevertheless made the latter the essential considerwords in a dictionary. Add to all this, the liveliness of his ation; instead of defining his classes and orders by a few imagination, the skill with which he applied his botanical artificial marks, he formed them from a view of all knowledge to practical objects, and the ingenuity he showed the most essential parts of structure; and thus he colin turning to the purposes of his classification the newly- lected under the same divisions all those plants which are discovered sexes of plants, and we shall at once comprehend most nearly allied to each other. Hence while a knowledge what it was that exalted Linnæus so far above his contem- of one plant does not by any means lead to that of another poraries. But great as the impulse undoubtedly was which in the system of Linnæus, it leads directly to the knowledge Linnæus gave to botany, there were vices in his principles of many more in the classification of Jussieu; which has which, although overlooked during his life, have subse- accordingly gained the name of the natural system. This quently been productive of infinite evil. There is no such at once brought the science back to a healthy state; it thing as a rigorous definition in natural history: this fact demonstrated the possibility of reducing the characters of Ray had demonstrated to arise out of the very nature of natural groups to words, contrary to the opinion of Linnæus, things; and consequently the short phrases by which spe- who found that task altogether beyond his powers; it did cies and genera were characterized by Linnæus were found away with the necessity of artificial arrangements, and equally applicable to many other plants besides those for giving a death-blow to verbal botany, it laid the foundation which they were intended: hence arose a new source of con- of that beautiful but still imperfect superstructure, which fusion, inferior only to that which it was intended to correct. has been erected by the labours of Brown, De Candolle, Differential characters, which would be invaluable if we had and others. If the system of Jussieu were not a return all nature before us, were found in practice to lead to inces- to that of Ray, modified only and improved by modern dissant errors, so soon as some new species was introduced into coveries, we should certainly have taken this period for the the calculation: they also laboured under the great fault commencement of of conveying no idea whatever of the general nature of the plants to which they related: thus the Portuguese botanist Loureiro, who attempted to determine the plants of China by the systematic writings of Linnæus fell into the singular error that the hydrangea was a primrose. With regard to his artificial system of classification, it was found that it looked better in the closet than in the field; that the neatness and accuracy of the distinctions upon which it was divided into groups existed only upon paper, and that exceptions without end encumbered it at every turn. This, which is perhaps inseparable from all systematic arrangements, would not have been felt as so great an evil, if there had been any secondary characters by which the primary ones could be checked, or if the system had really led with all its difficulties to a knowledge of things. But it was impossible not to perceive that it led in reality to little more than a knowledge of names, and that it could be looked upon as nothing beyond an index of genera and species. Let us repeat, however, that these objections were of little weight in the time of Linnæus; the force of many of them was hardly felt, when scarcely a twelfth part of the species now known to exist was upon record; and the world was naturally inclined to embrace with ardour the clearness and precision of the Linnean language, notwithstanding all its faults, in exchange for the cumbrous, vague, or unmethodical descriptions of those who preceded it. The great evil that has arisen out of the system of Linnæus has been this: that it has led to the formation of a large school of

The sixth and latest era in our science. But it was reserved for a man whose fame lies chiefly in the literary world to effect the last great_revolution that the ideas of botanists have undergone. In 1790, one year after the appearance of Jussieu's Genera Plantarum, the German poet Göthe published a pamphlet called 'The Metamorphosis of Plants. At that time the various organs of which plants consist had been pretty well ascertained, the distinctions between the leaf, the calyx, the corolla, the stamens, and the pistil, were in a great measure understood, and the botanists were not a few who fancied there was nothing more to learn about them. Nevertheless even in the time of Theophrastus a notion had existed that certain forms of leaves were mere modifications of others that appeared very different, as the angular leaves in croton of the round cotyledons or seminal leaves of that plant. Linnæus himself had entertained the opinion that all the parts of a flower are mere modifications of leaves whose period of development is anticipated (prolepsis plantarum); Ludwig in 1757, and more especially Wolff in 1768, had stated in express terms that all the organs of plants are reducible to the axis and its appendages, of the latter of which the leaf is to be taken as the universal type. But the theory of Linnæus was fanciful; Ludwig was a writer of too little authority in his day to succeed in establishing a doctrine so much at variance with received opinions; and the theory of Wolff was propounded in a paper upon the formation of the intestines in animals, which

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