Page:Popular Science Monthly Volume 28.djvu/722

704 With the rapid development of the science successive editions appealed, each for the most part rewritten, the fifth edition coming out in 1857. Hut botanical science at length outgrew the possibility of dealing with it in any adequate way in a single volume. This led to the necessity of completer treatment in several connected works. Professor Gray says in his preface: "To secure the requisite fullness of treatment of the whole range of subjects it has been decided to divide the work into distinct volumes, each a treatise by itself, which may be independently used, while the whole will compose a comprehensive botanical course."

The first volume of this series was written by Professor Gray, and entitled "The Structural and Morphological Botany of Phanerogamous Plants." It deals chiefly with organography, or the account of the structures and forms of the organs of plants, and, as the author remarks, "should thoroughly equip a botanist for the scientific prosecution of systematic botany, and furnish needful preparation to those who proceed to the study of vegetable physiology and anatomy, and to the wide and varied departments of cryptogamic botany" which arc to be dealt with in the subsequent volumes of the series.

The second volume of this work upon "Physiological Botany" (vegetable histology and physiology), the treatise now before us, was written by Professor Goodale, the colleague of Professor Gray, and Professor of Botany in Harvard University, and is "devoted to a consideration of the microscopic structure, the development, and the functions of flowering plants; that is, to their vegetable histology, organogeny, and physiology." The volume is divided into two parts, the first taking up and pursuing with great thoroughness the subject of histology, or the minute microscopical structure and elements of plants. An introduction is devoted to "Histological Appliances," or the instruments of the botanical investigator—such as microscopes, dissecting implements, reagents, etc. Cells and tissues, in their structures, contents, compositions, and modifications, are then taken up in a general way, to be followed by the minute structure and development of root, stem, and leaf, flower, fruit, and seed. Elementary structures being mastered, the pupil then proceeds, in Part II, to the investigation of their functions, or physiological botany proper. Physiology considers the plant in action, the changes occurring in its multitudinous parts, the constituents involved, the products generated, the interactions of the vegetable organism with soil and air, the movements of plants, vegetable growth, germination, and reproduction.

What chiefly strikes us, in looking over this interesting volume, is the immense advance that has been made in late years in the elucidation of the laws of the internal vegetable economy. There has been a large increase in the resources of investigation, the skillful experience with which it is conducted, and a great amount of new light has been thrown upon the obscure and subtile processes of vegetable organisms. Vegetable physiology has been brought far more completely within the grasp of the experimental method than would have been thought possible thirty years ago. It has become laboratory-work, as established and necessary as in the case of chemistry or physics. It follows from this that to the thorough study of physiological botany not only microscopical observation but manipulatory exercises of various kinds are quite indispensable. It was formerly supposed that the physiology of plants was a subject to be mainly read about, and the knowledge of it derived from books, without much possibility of a direct and real acquaintance with the facts, but that view must now be abandoned. We observe with interest and great satisfaction that Professor Goodale has been fully alive to the educational implications of this circumstance, and has made his volume a working text-book by which the student is enabled and required to make the knowledge of the subject his own. Those who faithfully go through the work will not only acquire a mastery of the facts, and a thorough acquaintance with what is known of the processes of vegetal life, but they will gain a valuable training in the conditions of scientific method and the difficult and important art of scientific investigation.

We can not close this slight and very unsatisfactory notice of a most important book without some cordial recognition of