CORRESP. MEMBER OF THE ROYAL ACAD. SC. BERL, AND ROYAL HORT. SOC. LIÉGE; HONORARY MEMBER OF THE BATAV. Soc. Sc., NAT. HIST. SOC. HAMB., LYC. NAT. HIST. N. YORK, AND HORT. SOC. OF BERLIN, N. YORK, TORONTO, ETC.; MEMBER OF THE IMP. ACAD. NAT. CUR., LINN. SOC. STOCKH., BOT. SOC. RATISB., PHYSIOGR. SOC. LUND., ETC.; VICESECRETARY OF THE HORTICULTURAL SOCIETY OF LONDON.

PROFESSOR OF BOTANY IN THE ROYAL INSTITUTION OF GREAT BRITAIN, TO THE SOCIETY OF APOTHECARIES, AND IN UNIVERSITY COLLEGE,

LONDON.

With Sir Copper-Plates and numerous Wood-Engravings.

THIRD EDITION,

WITH CORRECTIONS AND NUMEROUS ADDITIONS.

LONDON:

PRINTED FOR

LONGMAN, ORME, BROWN, GREEN, AND LONGMANS,

PATERNOSTER-ROW.

CENT

PREFACE.

ABOUT three centuries have elapsed since one of the earliest introductions to Botany upon record was published, in four pages folio, by Leonhart Fuchs, a learned physician of Tubingen. At that period Botany was nothing more than the art of distinguishing one plant from another, and of remembering the medical qualities, sometimes real, but more frequently imaginary, which experience, or error, or superstition, had ascribed to them. Little was known of Vegetable Physiology, nothing of Vegetable Anatomy, and even the mode of arranging species systematically had still to be discovered; while scarcely a trace existed of those modern views which have raised the science from the mere business of the herb-gatherer to a station among the most intellectual branches of natural philosophy.

It now comprehends a knowledge not only of the names and uses of plants, but of their external and internal organisation, their anatomy and physiological phenomena: it involves the consideration of the plan upon which those multitudes of vegetable forms that clothe the earth have been created, of the combinations out of which so many various organs have emanated, of the laws that regulate the dispersion and location of species, and of the influence exercised by climate upon their developement; and, lastly, from botany as now understood, in its most

extensive signification, is inseparable the knowledge of the various ways in which the laws of vegetable life are applicable to the augmentation of the luxuries and comforts, or to the diminution of the wants and miseries, of mankind. It is by no means, as some suppose, a science for the idle philosopher in his closet; nor is it merely an amusing accomplishment, as others appear to think; on the contrary, its field is in the midst of meadows, and gardens, and forests, on the sides of mountains, and in the depths of mines, - wherever vegetation still flourishes, or wherever it attests by its remains the existence of a former world. It is the science which converts the useless or noxious weed into the nutritious vegetable; which changes a bare volcanic rock into a green and fertile island ; and which enables the man of science, by the power it gives him of judging how far the productions of one climate are susceptible of cultivation in another, to guide the colonist in his enterprises, and to save him from those errors and losses into which all such persons unacquainted with Botany are liable to fall. This science, finally, it is which teaches the physician how to discover in every region the medicines that are best adapted for the maladies prevalent in it; and which, by furnishing him with a certain clue to the knowledge of the tribes in which particular properties are, or are not, to be found, renders him as much at ease, alone and seemingly without resources, in a land of unknown herbs, as if he were in the midst of a magazine of drugs in some civilised country.

The principles of such a science must necessarily be complicated, and in certain branches, which have only for a short time occupied the attention of observers, or which depend upon obscure and ill-understood evidence, are less clearly defined than could be

wished. To explain those principles; to adduce the evidence by which their truth is supposed to be proved, or the reasoning upon which they are based in cases where direct proof is unattainable; to show the causes of errors now exploded, the insufficiency of the arguments by which doubtful theories are still defended, and, in fine, to draw a line between what is certain and what is doubtful, are some of the objects of this publication, which is intended for the use of those who, without being willing to occupy themselves with a detailed examination of the vast mass of evidence upon which the modern science of botany is founded, are, nevertheless, anxious to acquire a distinct idea of the nature of that evidence. Another and not less important purpose has been to demonstrate, by a series of well-connected proofs, that in no department of natural history are the simplicity and harmony that pervade the universe more strikingly manifest than in the vegetable kingdom, where the most varied forms are produced by the combination of a very small number of distinct organs, and the most important phenomena are distinctly explained by a few simple laws of life and structure.

In the execution of these objects, I have followed very nearly the method recommended by the celebrated Professor De Candolle, than whom no man is entitled to more deference, whether you consider the soundness of his judgment in all that relates to order and arrangement, or the great experience which a long and most successful career of public instruction has necessarily given him.

I have begun with what is called ORGANOGRAPHY (Book I.); or an explanation of the exact structure of plants; a branch of the subject comprehending what relates either to the various forms of tissue of