Botany.

covery of new plants or through phytotomical and physiological research: it also evidently requires the greatest scientific attainments and the highest powers of a philosophic mind. Nor is it one of the least of the practical difficulties, that the affinities of plants are not such as to constitute a simple lineal series, but that they may be viewed as a multitude of groups arranged around centers, and connected with each other upon different sides and by a great variety of ties.

Yet the rudiments of a natural system have always been sought after, and in some measure attained, when B. has been studied as a science-whenever it has become anything more than a mere acquaintance with a few plants and their names. The genera into which species are grouped by all botanists are natural, and are the basis upon which all classification proceeds in its further generalizations. So sensible was Linnæus of the importance of maintaining this character of the genera, that when a rigid adherence to his artificial system would have caused the division of a genus into parts, and the consequent separation of species very nearly allied, he kept the genus unbroken, and maintained the usefulness of his artificial system, to the student desirous of finding the names of plants, by referring from one of its classes or orders to another for species exceptional among those of their genus as to the number of their stamens or pistils, or their diœcious, monacious, or hermaphrodite flowers.-The classification of species, however, in genera and larger natural groups, being a subject as much connected with other branches of natural history as with B., will more properly be treated in the article NATURAL HISTORY; and to that article also, and to the article SPECIES, we refer for all that our limits allow concerning some of the most interesting and difficult questions of science, the limits of species, the distribution of species, etc.

An important branch of botanical science is that which is called geographical B., or the geography of plants, and sometimes phytogeography. It must be regarded as yet in its infancy, although a multitude of observations have been recorded in works of descriptive B., and by botanical travelers. It is the object of geographical B. to connect with the occurrence or prevalence of plants in particular countries a great variety of facts as to climate, altitude, geology, etc., and even facts of history. It aims at the establishment of great general laws, which, however, it has not yet been able to establish. Some account of the progress which has been made in this branch of B., and of the imperfect generalizations which have been reached, will be found in the article GEOGRAPHICAL DISTRIBUTION.

Another branch of botanical science which has recently sprung up, and has acquired great magnitude and importance, is PALEONTOLOGICAL B., or FOSSIL BOTANY. The petrified fruits and wood, the beautiful impressions of ferns and palms, and other traces and remains of former vegetation, which appear in vast numbers and great variety in different strata of the earth's crust, present a most interesting field of scientific research. The study of the different kinds of fossil plants, and the comparison of them with existing species, belong strictly to the science of B.; the study of their relations to particular strata or formations, and so to particular periods in the physical history of the globe, belongs to geology. The study of fossil plants has proved exceedingly useful in guiding to just and philosophic views of the mutual relations even of species and groups still existing. See PALEONTOLOGY,

The subject of the DISEASES OF PLANTS must be regarded as falling within the province of botany. It has scarcely yet been treated or studied as a distinct branch of science, although it has not been overlooked in its relation to vegetable physiology, with which its intimate connection is obvious, and it has received no little attention in its bearings on agriculture and other arts by which plants are made to supply the wants or minister to the comforts of man.

ECONOMIC B. includes all that relates to plants, considered with reference to these arts and to these uses. That part of it which relates to medicinal plants has been often separately and elaborately treated under the name of MEDICAL BOTANY. In the botanical articles of this work will be found notices of the more important plants affording food to man, and therefore cultivated in fields or gardens, in warm or in cold climates, and of those valuable for their timber, their fiber, or the dye-stuffs or medicines which they yield.

Having thus endeavored to sketch an outline of the science of B., we must refer to the articles PLANT, VEGETABLE PHYSIOLOGY, instead of attempting here to fill up a part of that outline by exhibiting the first principles of the science. It remains for us, in the present article, to give a very brief account of the history of B., and outlines of the systems of classification most deserving of attention.

His

We are informed that Solomon "spoke of trees, from the cedar in Lebanon even to the hyssop that springeth out of the wall." There is reason also to believe that Zoroaster devoted some attention to plants, and that this study early engaged some of the philosophers of Greece. The oldest botanical work which has come down to us is that of Theophrastus (q.v.), a pupil of Aristotle, who flourished in the 4th c. B.C. descriptions of plants are very unsatisfactory, but his knowledge of their organs and of vegetable physiology may well be deemed wonderful, when we consider the low state of this branch of science throughout many centuries after his time. It was not, indeed, till after the revival of letters in western Europe, that it was ever again studied as it had been by him. About four hundred years after Theophrastus, in the first c. of the

Christian era, Dioscorides of Anazarbus, in Asia Minor-a herbalist, however, rather than a botanist-described more than 600 plants in a work which continued in great repute throughout the middle ages, a sure proof how destitute that period must have been of any botanical science of its own. About the same time, the elder Pliny devoted a share of his attention to B., and his writings contain some account of more than 1000 species, but compiled from various sources without much discrimination, and mingled with many errors. Centuries elapsed without producing another name worthy to be mentioned in a history of botany. It was among the Arabians that the science next began to be cultivated, about the close of the 8th century. The greatest name of this period is Avicenna. Centuries again elapsed, a longer interval than before, during which it made no progress whatever. It was not till the beginning of the 16th c. that B. resumed its place as a science. The first to revive it was Otto Brunsfels, a German, who published in 1530 his Historia Plantarum Argentorati, or history of the plants of Strasburg, in 2 vols., folio, illustrated with cuts. He was speedily followed by Bock or Tragus, Fuchs or Fuchsius, and other Germans; by Matthiolus and Cæsalpinus in Italy; Dodons or Dodonæus in the low countries; De L'Obel or Lobelius, a Dutch physician at the court of England; Gesuer in Switzerland; Dalechampa and Moulins, or Molinæus, in France, and by many others, for B. now began to be prosecuted wherever learning flourished, and with great zeal and success. Chairs of B. were founded in universities, botanic gardens (q. v.) were established in many places, and travelers began to explore even remote parts of the world. One of the greatest names of the latter part of the 16th c. is that of L'Ecluse, or Clusius, who traveled through many countries, encountering great perils and hardships in pursuit of his favorite science, and was finally professor of B. at Leyden. The name of Dr. Turner, "the Father of English B.," belongs more to the 17th c. than to the 16th. The number of species known and described had increased, in the beginning of the 17th c., to more than 5000, but the study of them was much impeded by confusion of synonyms and by want of classification, whilst classification was rendered extremely difficult by imperfect knowledge of the structure and organs of plants. The foundations of a natural system of classification may be said to have been laid, in the latter half of the 17th c., by Dr. Robert Morison, a native of Aberdeen and professor of B. at Oxford, followed towards the close of the century by the celebrated Ray, one of the greatest naturalists that England has produced.

The application of the microscope in B. inaugurated a new epoch of the science, about the middle of the 17th century. Henshaw and Hook, both Englishmen, were among the first to employ this instrument to good purpose in the examination of the organs and structure of plants; but the greatest eminence belongs to the name of Grew, also an Englishman, a physician at Coventry, and to that of Malpighi, an Italian, perhaps still more celebrated for his anatomical than for his botanical discoveries. Vege table physiology now began to be recognized as the highest department of botanical science.

In the latter half of the century, perhaps the most eminent name after Ray is that of Joseph Pitton de Tournefort, a French gentleman, who devoted his whole life to the pursuit of botanical science, and who must be particularly noticed in a sketch of the history of B., on account of a system which he proposed, and which was more generally received and employed than any other till the time of Linnæus. Another botanist of the same period, Rivinus, professor at Leipsic, gave to the world a botanical system which was received to some extent in Germany. Tournefort's system was partly natural and partly artificial; that of Rivinus was perhaps the most perfectly artificial that was ever proposed.

The science of B. made rapid progress during the 17th and 18th centuries, both by the extension of botanical research in different parts of the world, and the careful study of particular groups of families of plants. Its progress was promoted by the publication of many valuable descriptive works. Important discoveries were also made in vegetable physiology.

About the middle of the 18th c., the wonderful genius of Linnæus effected a great change in B., as well as in zoology. His name marks an epoch in the history of the science; not chiefly, however, in consequence of the new system which he introduced, nor even because of the discoveries which he made, but rather because he was able very thoroughly to make himself master of all that had been ascertained by his predecessors, and to exhibit it in lucid order. He gave also a great impulse to botanical studies by the enthusiasm with which he inspired his pupils. And among the benefits which he conferred on B., in common with zoology, not the least considerable was the introduction of trivial or specific names to be used along with the name of the genus as the designations of particular species.

From the time of Linnæus, the progress of B. during the remainder of the 18th c. became more rapid; and since the commencement of the 19th c., it has advanced with gigantic strides. A large space would be occupied by a mere enumeration of the names of those who have promoted it by their labors and discoveries. Some notion of what botanical literature has become, may be formed from the fact that Pritzel, in his Thesaurus Litteratura Botanica (Leip. 1847-51), enumerates about 15,000 publications. Von Haller, an anatomist and philosopher, as well as a botanist, was, of all the contemporaries of Linnæus, the only one who could be regarded as his rival. Of all the

Botany. botanists of the latter half of the 18th c., the most deserving to be mentioned in the history of the science along with the great Swede, are Bernard de Jussieu and his nephew, Antoine Laurent de Jassieu, who applied themselves with great earnestness to the study of the natural affinities of plants and the formation of a natural system, a work which Linnæus himself attempted, and of the importance of which he was so sensible, that whilst acknowledging the imperfect success of his endeavors, he declared his resolution to persevere in them to the end of his life. The Jussieus traced the outlines of a system which the greatest botanists since their time have not so much sought to change as to complete. Among those who have labored with greatest success in this work, must be mentioned De Candolle, Fries, Endlicher, Brougniart, Meisner, Von Martius, Lindley, and Brown. The botanist last named acquired by his work on the plaats of New Holland, published in 1810, a high eminence, not on account of new plants which he described, but on account of the light which he threw upon the most difficult questions connected with the structure of plants and vegetable physiology. Many remarkable discoveries in vegetable physiology have recently been made by Link, Meyen, Schleiden, Von Mohl, Lindley, and others, some of them affecting what may be called the most fundamental principles of botanical science.

Since the days of Linnæus, great progress has been made in the examination of the B. of particular countries and districts, of which perhaps the least important result has been the discovery of very many plants unknown before. But our limits prevent us from noticing particular works in this department of botanical science, or those of botanical travelers, or of botanists who have devoted themselves to the study of particular groups of plants. And we can merely allude to the scientific associations, continually increasing in number and resources, by which the interests of this science are promoted, and to the magazines and other periodical publications devoted to it. However, we cannot but refer also to what may be deemed by some—but unjustly—matters of comparative insignificance, the introduction of B. into schools, and the publication of many works intended for the use of persons not very scientific. By the introduction of this or any similar branch of science into schools, not only may important educational purposes be served, but the young may be led to form a taste for the science which will impel them to its subsequent prosecution. There are few branches of science so easily made popular as B.; but they very much mistake its nature who suppose it to consist in a mere knowledge of the names of plants, or in a familiarity with the classes of an artificial system. What B. really is, and to what the true study of it tends, is better perceived if we consider that "there is not a flower that blows but has some beauty only unveiled to the minute inquirer, some peculiarity in structure fitting it to its destined place and purpose, and yet not patent to a casual glance." There is perhaps no branch of science which demands more than B. the application of the highest mental powers; and like every other, to him who truly prosecutes it-whether little or much-it brings in due measure an immediate reward in his own improvement and delight.

We proceed to exhibit an outline of the Linnæan system, the only artificial system which it appears necessary further to notice, and of the natural system by which it has been to a great extent superseded. The Linnæan system, however, is not entirely artificial. Its foundation may be said to be laid in the perfectly natural distinction between Phanerogamous and Cryptogamous plants-the former of which Linnæus divided into 23 classes; while he constituted the latter, corresponding to the Acotyled onous plants of Jussieu, into his 24th and last ciass, Cryptogamia. In the other classes, he took the characters from the parts of fructification: this he defined as having no stamens or pistils distinctly visible, and gave it a name, Cryptogamia (Gr. kryptos, concealed, and game, marriage), in accordance with this definition, modestly refraining from a confident assertion of the absence of stamens and pistils. Of the 23 classes of phanerogamous or phenogamous plants (Gr. phaneros, manifest, and phaino, to show), the characters of all are taken from the stamens; and those of Classes I. to XI., simply from the number of them; these classes, however, not including plants exhibiting the peculiarities with reference to which the remaining classes are constituted. Thus Class I.. Monandria (Gr. monos, one, aner, a male), consists of plants the flowers of which have only one stamen; Class II., Diandria (Gr. dis, twice), of those with two stamens; Class III., Triandria (Gr. treis, three), of those with three stamens, and so on; Class IV., Tetrandria (Gr. tetras, four times); Class V., Pentandria (Gr. pente, five); Class VI., Hexandria (Gr. hex, six); Class VII., Heptandria (Gr. hepta, seven); Class VIII., Octandria (Gr. octo, eight); Class IX., Enneandria (Gr. ennea, nine); Class X., Decandria (Gr. deka, ten)-until, in Class XI., Dodecandria (Gr. dodeka, twelve), the number of the stamens is less definitely fixed, and plants are included in it having more than ten, and fewer than twenty stamens. Then follow two classes-Class XII., Icosandria (Gr. eikosi, twenty), and Class XIII., Polyandria (Gr. polys, many)—which have numerous stamens, but differ in their being inserted on the calyx in the former class, and on the receptacle in the latter, characters essentially natural, as are those also of most of the remaining classes. Classes XIV., Didynamia, and XV., Tetradynamia (Gr. dynamis, power), arc distinguished by having the stamens of different lengths-the former having two long and two short stamens, the latter, four long and two short. Class XV. agrees with the great natural order Cruciferæ. Class XVI., Monadelphia (Gr. adelphos, a brother), has

Botany.

the stamens united by the filaments in one bundle; Class XVII., Diadelphia, has the filsments united in two bundles, or one free and the rest united; Class XVIII., Polyadelphia, has them united in more than two bundles. In Class XIX., Syngenesia (Gr. syn, together, and genesis, generation), the stamens are also united, but by the anthers instead of the filaments. This class nearly agrees with the great natural order Composite, and consists chiefly of plants having compound flowers. Class XX., Gynandria (Gr. gyne, a female), consists of plants in which the stamens grow out of, or are united with the pistil. Class XXI., Monacia (Gr. oikos, a house), consists of plants having the stamens and pistils in different flowers on the same plant; Class XXII., Diacia, of those which have the male and female flowers on different plants; Class XXIII.. Polygamia (Gr. polys, many, gamos, marriage), of those having the stamens and pistils in the same or in different flowers on the same or on different plants.-The classes are divided into orders, which are constituted on various grounds. The orders of the first 13 classes are strictly artificial, their characters being found simply in the number of the pistils, according to which they are named Monognia (Gr. monos, one, gyne, a female), Digynia, Trigynia, etc.; Dodecagynia, including all with 12 to 19 pistils, and Polygynia, all with 20 and upwards. The orders of Class XIV. are constituted on entirely different grounds, and are two in number, Gymnospermia (Gr. gymnos, naked, sperma, a seed), and Angiospermia (Gr. angeion, a vessel)—the former "having naked seeds" (or rather the fruit formed of 4 achenia), the latter having the seeds in a capsule. The orders of Class XV. are in like manner founded upon the fruit; those of Classes XVI., XVII., and XVIII. upon the number of the stamens; as are also those of Classes XX., XXI., and XXII.; those of Class XIX., chiefly upon characters taken from the florets of compound flowers; those of Class XXIII., upon the circumstance of the hermaphrodite, male and female flowers being found on one, two, or three plants; whilst the orders of Class XXIV. are strictly natural-Filices (or ferns), Musci (or mosses), Alga, and Fungi. The student may acquire a pretty complete knowledge of the Linnæan artificial system, without knowing much in reality of B.; but, even in beginning to learn the natural system, he must learn some of the first principles of the science. Jussieu followed Ray in dividing plants into three great primary divisions—acotyledones (q.v.), monocotyledones (q.v.), and dicotyledones (q. v.); having respectively no cotyledon or seedlobe, one cotyledon, and two cotyledons. And, however the names may be changed, or characters assumed from other parts of the plant, these great divisions of the vegetable kingdom still subsist; the acotyledonous plants being also, according to characters taken from the stem, acrogenous (q.v.); the monocotyledonous plants, endogenous (q.v.); and the dicotyledonous plants, exogenous (q.v.). Endlicher is the only botanist of great note who has attempted to make primary divisions of the vegetable kingdom essentially dif ferent from those indicated by Ray, and his attempt has not commended itself to general approval. De Candolle gave expression to an important truth in botanical science, when he united the two divisions of monocotyledonous and dicotyledonous plants under the common title of vascular plants, in opposition to acotyledonous or cellular plants; the vascular plants being the phanerogamous, and the cellular the cryptogamous. Lindley has endeavored to modify the natural system by dividing the asexual or flowerless (cryp togamous) plants into the two classes of thallogens-with the stem and leaves undistinguishable and acrogens, with the stem and leaves distinguishable, thus limiting the term acrogens to those which have a distinct stem; and in like manner dividing the sexual or flowering (phanerogamous) plants into five classes, viz., rhizogens, with fructification springing from a thallus; endogens and dictyogens, with fructification springing from a stem, the wood of which is youngest in the center, and the seed with a single cotyledon the former having parallel-veined permanent leaves, and the wood of the stem always confused; the latter having net-veined deciduous leaves, and the wood of the stem when perennial arranged in a circle around a central pith; gymnogens and exo gens, having the wood of the stem youngest at the circumference, and always concentric, the seed with two or more cotyledons; the former having the seeds quite naked, the lat ter having them inclosed in seed-vessels. But others generally prefer the simpler division of phanerogamous or vascular plants into monocotyledonous or endogenous, and dicotyledonous or exogenous, the former including Lindley's endogens and dictyogens, the latter his exogens, gymnogens, and rhizogens; although the latter have only a provisional place assigned them, in the absence of well-ascertained views of their structure.

One of the great advantages of the natural system is, that the plants which it brings together are very generally found to agree in their properties, as well as in their structural characters. There are, indeed, species which, in respect of their properties, are anomalous or exceptional in the genera or orders to which they belong; but these exceptions do not invalidate the general rule, according to which we expect the most deadly poisons in the order loganiacea, bland mucilage and useful fiber in malvacea, wholesome succulent herbage along with a certain amount of acridity or pungency in crucifera, etc., etc. The knowledge of the properties of genera and orders is of great use in guiding inquiry, and it is thus that modern science attains in rapid succession to discoveries important in their practical relations.

In the determination of the intermediate subdivisions of the natural system, botanists have not yet been so successful as with regard to these primary divisions, and the ascer