LECTURE XLIV.

HISTORY OF BOTANY FROM THE BEGINNING OF THE SIXTEENTH CENTURY TO THE TIME OF LINNÆUS.

We have now traced the progress of botanical knowledge, from the earliest periods of the world, to the discovery of America. About this time, botanic gardens began to be cultivated; these afforded new opportunities for investigation, by comprehending the vegetables of all countries within such limits as enabled the botanist to compare them, and to watch their growth and different stages of development.

From the days of Theophrastus until the beginning of the 16th century, Botany, instead of becoming more perfect, had been rendered more obscure. This was not owing to want of attention or labour, but to the false rules of philosophy which had so long prevailed.

At length the cause of the evil seemed to be discovered. Many writers protested against the erroneous opinions of their times; they said, Four blind respect for the ancients is an insurmountable obstacle to the progress of Botany. We expect to find everywhere the plants of Theophrastus, Dioscorides, and Pliny; whereas they did not know one hundredth part of the plants which cover the globe. The first of them never went out of Greece; the second left only unconnected notes, treating without order upon the medicinal qualities of plants; and Pliny copied these notes without comment or criticism. We cannot apply to the plants of Germany or France, the names under which the ancients described those of Italy, Greece, and Asia; before studying the plants of foreign countries, we ought to know those of our own. Of what use are disputes about the nature and qualities of species, when we are not able to distinguish one from another? The true method of doing this, is to explore the plains, valleys, and mountains, to examine and compare the plants of our own and foreign countries. Libraries alone are insufficient to make botanists."

These reflections led to a happy revolution, not only in this science, but in all others; it may be called the era of true philosophy.* Yet the principles which were now discovered, were not much applied to science until the time of Bacon, Newton, Linnæus, and Locke; and it remained for the late Dr. Thomas Brown, of Edinburgh, to show that the human mind itself is subject to the same general laws of inquiry which now regulate investigations in the physical sciences.

Up to the period of which we are now speaking, plants had only been described in alphabetical order; about this time, some German botanists attempted a collection of individual plants into species; this improvement was received with much approbation. Y

* Lord Bacon is generally considered as having first taught the proper method of studying the sciences, viz. by ascending from facts to principles; this is called the method of induction. It has recently been asserted by an able writer in one of our first American periodicals, that Bacon was not the author of the inductive philosophy, but that he borrowed his rules of philosophizing from Aristotle, whose real principles had for ages been misunderstood. It is to be hoped that men of talents will not so far depart from the true rules of philosophizing, as to devote that time in contending about their author, which might be profitably applied in the application of these rules to the investigation of truth and nature.

Botanic gardens first cultivated-Botanists began to discover the obstacles to the progress of science-Era of true philosophy-Improvements of German botanists.

These species were arranged according to certain general resemblances, or natural relations; thus we see that natural methods were prior to any attempts at an artificial system.

In the beginning of the 16th century, we find the names of many who were engaged in investigating the vegetable kingdom. Some are commemorated by the names of plants; Leonard Fuschs of Germany, by the plant Fuschsia ; Lobelius, physician to James I., by the Lobelia; and Lonicer, by the Lonicera.

Lobelius distinguished the cotyledons of seeds, divided monocotyledonous from dicotyledonous plants, and attempted to form families by grouping species according to their natural relations. Zaluzian of Bohemia laboured to perfect the natural groups of former botanists; he is the first of the moderns who positively affirmed the existence of stamens and pistils in all species of plants, and suggested the necessity of these organs.

But, notwithstanding the labours of many learned men, little real improvement would have been made in the science of Botany, had there not, at that time, existed some minds of superior genius, who turned their attention to tracing some proper method of classification. These were Gesner, Clusius, Casalpinus, and Bauhin; of the latter name were two brothers, both of whom are deservedly celebrated.

Gesner, called the Pliny of Germany, born in 1516, was of an obscure and humble origin, but possessed of a powerful and penetrating mind. He attempted to make a general collection of the objects of natural history; he explored the Alps, and discovered many plants until then unknown. He is distinguished from those who had gone before him, in his suggestions that there existed in the vegetable kingdom, groups, or genera, each one composed of many species, united by similar characters of the flowers and fruit. Soon after the publication of this opinion, botanists began to understand that the different families of plants have among themselves natural relations, founded upon resemblances and affinities, and that the most obvious are not always the most important. These are fundamental truths; and the distinction of species, the establishment of genera, and of natural families, seemed to follow of course, after these principles were once established. The Tulipa gesneriana, and genus Gesneria, have been dedicated to this botanist.

Clusius was born in 1526; his parents had destined him for the profession of law, but his decided taste for Botany induced him to abandon this profession. He was learned in the ancient and modern languages, but his enthusiasm for natural history induced him to lay aside every other pursuit. He travelled over almost all the west of Europe, in order to make discoveries in the vegetable kingdom; and soon excelled all the botanists of the age in the knowledge of both native plants and exotics. He had the direction of the imperial garden at Vienna, and afterward was public professor of Botany at Leyden. His enthusiasm for this science terminated only with his life. Before his time, the art of describing plants with precision and accuracy was unknown; but, unlike the descriptions of his predecessors, his were neither faulty from superfluous terms, nor from the omission of important circumstances.

Casalpinus, a native of Florence, who was contemporary with Clusius, proposed to form species into classes. The characters which

Botanists of the 16th century-Lobelius-Zaluzian-Gesner-How distinguished from his predecessors ?-Clusius, the first who proposed to divide plants into classes -Cæsalpinus.

he employed for this purpose, were, the duration and size of plants; presence, or absence of flowers; the number of cotyledons; the situation of the seed, as erect or pendent; the adherence of the pericarp to the seeds; the number of cells in the pericarp, and the number of seeds which they contained; the adherence of the calyx to the germ; and the nature of the root, whether bulbous, or fibrous. This method was too imperfect to be followed, having neither the simplicity nor the unity to render its application useful.

John Bauhin, though younger than Gesner, was his friend and pupil; he composed a general history of plants; this was a work evincing great learning and accurate investigations. Gaspard Bauhin, the younger brother, no less active and learned, conceived the design of a work which should contain a history of all known plants, together with the different names which other writers had applied to the same plant. Clusius and the elder Bauhin had imagined something like a genus of plants, formed by the grouping of similar species, but Gaspard Bauhin expressed this more decidedly in remarks upon generic distinctions. His work, the result of forty years' labour, was of great assistance to Linnæus, in perfecting our present system of Botany.

We find, in looking back upon the labours of botanists during the 16th century, that more had been accomplished than during any former period; the character of novelty and originality exhibited in these researches, is highly creditable to those who thus led the way in the march of improvement.

The 17th century, in its commencement, was not favourable to the sciences. Europe was agitated by continual wars, and the arts of peace were neglected; but in the last part of that age, a taste for natural history revived; men of highly gifted minds applied themselves to the study of Botany, and many undertook long voyages, with the sole design of examining foreign plants. Botanists were astonished at the great number of interesting plants discovered by travellers, in the region of South Africa, around the Cape of Good Hope, and in the East India Islands.

Two Dutch botanists of the name of Commelin, who wrote about this period, are commemorated in the beautiful genus Commelina, first discovered in America. Bonnet* of Geneva, a close observer of facts, wrote upon the "Nature and Offices of Leaves;" and a work entitled, "Contemplation of Nature, or the Regeneration of Beings." Two writers of the name of Camararius are distinguished in the annals of the science for learning and ingenuity. Gaertner of Germany wrote upon fruits, or, as he termed this department of the science, Carpology, He dissected the fruits of more than a thousand plants, the figures of which he designed and engraved. To Gleditsch, professor of Botany at Frankfort, is dedicated the genus Gleditscha. Rudbeck the younger, who preceded Linnæus as professor of Botany in Upsal, was, by the latter, commemorated in the genus Rudbeckia.

At this period, the plants of our own country began to excite the curiosity of scientific Europeans. Louis XIV. sent to America, Plumier, a man celebrated for his mathematical and botanical knowledge, and who was styled, botanist to the King. He made three voyages, and gave drawings and descriptions of more American species than any other traveller had done.

* Pronounced Bonnay.

Characters employed by him in the formation of classes-The Bauhins-Retrospect of the 16th century-Botany in the 17th century.

About this time, the practice of naming newly-discovered plants after distinguished botanists became common. History now presents us with many who were distinguished by their efforts in the cause of science, but a notice of each individual would carry us beyond our limits.

Botanists now began to study the stamens and pistils of plants; and it was suggested that the science would remain imperfect as long as species and genera were undefined. Orders and classes also were recommended, and natural resemblances and affinities studied. A work was written upon the umbelliferous plants ;* this was the first attempt at describing in one mass any single group of plants by characters peculiar to the whole. This was followed by several attempts to form a natural method of classification; among the most approved of these methods was that of Ray, who published a work called "A General History of Plants ;" in this he divided all Plants into 33 classes, 27 of which were composed of herbs, the rest of

trees.

The first botanist who thought of classing plants without any reference to their being either herbs or trees, was a German, of the name of Rivannus, who proposed to consider, as the foundation of classification, the absence or presence of flowers; the manner in which they were situated, or their inflorescence; the number of petals; the regular or irregular form of the corolla; the adherence or non-adherence of the calyx to the germ; the nature of the pericarp; the number of seeds, and of cotyledons.

A botanist of the name of Magnol, at this time, was honoured by having his name given to the splendid Magnolia, an American plant, which then began to be known in Europe.

Joseph Pitton de Tournefort was born in 1656. While very young, he discovered an enthusiastic fondness for botanical pursuits: he had been destined by his friends for a profession; but his genius seemed so strongly bent upon the study of nature, that he was at length permitted to indulge without restraint in his favourite pursuits. He ranged over the Alps and Pyrenees, and many provinces of France, collecting the flowery treasures offered by those fertile regions; often in peril from banditti, and exposing his life to hazards in climbing terrific precipices, or amidst the glaciers of the mountains.

The method of Tournefort, which was founded upon the form of the corolla, although imperfect, greatly assisted the progress of that botanist who stands unrivalled in this department of Natural History. You do not need to be told that we here refer to Linnæus. You will observe that the attempts of botanists, until this time, had been chiefly directed towards the attainment of some proper method for the arrangement of plants; the attention of some investigating minds was now turned towards their Anatomy and Physiol ogy. Since the days of the first Greek naturalists, these departments of botanical science had lain neglected; but the confused opinions of the ancients now served to suggest experiments, which resulted in new observations and solid discoveries.

The invention of the microscope threw light upon the mysteries of

*The author of this was Robert Morrison, a Scotchman. These monographs, or descriptions of single families, are now of great value; no botanist can thoroughly investigate the whole vegetable kingdom; but by close attention to one department, important discoveries may be made.

Various improvements in Botany-Ray-Rivinius-Magnol-Tournefort-Attention of botanists turned towards anatomy and physiology-Microscope.

nature, which, without this instrument, must ever have remained in obscurity; by its assistance botanists studied the internal structure of vegetables; they described the heart, wood, and pith; they perceived the newly formed bud, yet invisible to the naked eye; the future plant existing in the bulbous roots, and even in the seed; pores were discovered, which were found to be the organs of the expiration and inspiration of gases, thrown out as noxious, or inhaled as nutritious.* The importance of the stamen and pistils as essential to the perfection of the seed of vegetables began to be suspected.

As yet, however, the science of Botany lay in scattered fragments of various imperfect and contending systems; much labour had been bestowed, and great improvements made, but there was no central point around which these improvements might be collected.

The learned world were sensible of the deficiency; but it required genius, great observation of nature, and courage to stem the tide of popular prejudices, in him who should come forward to attempt the work of reform.

Charles Von Linnæus, an inhabitant of Sweden, suddenly emerging from obscurity, offered to the world a system of Botany, so far superior to all others, as to leave no room for dispute as to its comparative merit. All preceding systems were immediately laid aside, and the classification of Linnæus was received with scarcely a dissenting voice. What this system was, you have not now to learn, since it was the alphabet of your botanical studies. Linnæus extended the principles of his classification to the animal and mineral kingdom; in the language of an eminent botanist, "His magic pen turned the wilds of Lapland into fairy fields, and the animals of Sweden came to be classed by him as they went to Adam in the garden of Eden to receive each his particular name."

LECTURE XLV.

HISTORY OF BOTANY FROM THE TIME OF LINNÆUS TO THE PRESENT.

LINNEUS was born in 1707; his father was a clergyman, and had designed his son for the same sacred office; but seeing him leave his studies to gather flowers, he inferred that he possessed a weak and trifling mind, unfit for close investigation; he was about to put him to a mechanical employment, when some discerning persons perceiving in his devotion to the works of nature the germ of a great and lofty mind, placed him in a situation favourable to the development of his peculiar talents, where he was allowed, without restraint, to study the book of nature,

"This elder Scripture, writ by God's own hand."

Linnæus formed anew the language of botanical science; every organ of the plant he defined with precision, and gave it an appropriate name; every important modification was designated by a particular term. Thus comparisons became easy, and confusion was avoided. The characters of plants appeared in a new light. Each species took, besides the name of the genus to which it belonged, a specific name which recalled some peculiarity distinctive of the * Leuwenhoek, Grew, Malpighi, and Camerarius, are among the first of the moderns who investigated the internal structure of vegetables.

† Sir James E. Smith.

Science of botany yet imperfect-Linnæus-Birth of Linnæus, &c.—What were the improvements made by Linnæus?