LINDLEY.-The Theory of Horticulture; or, an Attempt to explain the principal Operations of Gardening upon Physiological principles. By John Lindley. 8vo. London, 1840. A few wood-cuts. pp. 387. This is an application of Vegetable Physiology to practical purposes. MOQUIN-TANDON.-Eléments de Tératologie Végétale. Par A. Moquin-Tandon, M.D. 8vo. Paris, 1841. pp. 403. RICHARD.-Nouveaux Eléments de Botanique. Par Achille Richard, D.M.P. 8vo. Paris, 1846. 7th edition. About 900 wood-cuts. pp. 851. This work is adopted by the French Royal Council of Public Education. SCHLEIDEN.-Grundzüge der Wissenschaftlichen Botanik, nebst einer methodologischer Einleitung. Von M. J. Schleiden, M.D. 2nd edition, 2 vols. 8vo. Leipsig, 1845. 232 wood-cuts, 5 copper-plates. pp. 943. UNGER.-Grundzüge der Anatomie und Physiologie der Pflanzen. Von F. Unger, M.D. 8vo. Vienna, 1846. 77 wood-cuts. pp. 131. PART III.-MEDICAL AND ECONOMICAL BOTANY.* * This is in the press, and will appear in the course of the spring. THE ELEMENTS OF BOTANY. I.-GENERAL ATTRIBUTES. 1. PLANTS are scarcely separable from animals by any absolute character; the simplest individuals of either kingdom being often undistinguishable by our senses. 2. Animals are for the most part incapable of multiplying by mechanical or spontaneous division of their trunk, and are supported by nutritious matter, carried into their system from an internal bag or stomach. 3. Plants are for the most part congeries of individuals, multiplying by spontaneous or artificial division of their trunk or axis, and supported by nutritious matter conveyed into their system by (the absorption of their lower extremities or roots, or by) their outer surface. 4. Generally speaking, they are fixed to some substance, from which they grow, are destitute of locomotion, are enabled to digest their food by the action of light upon their skin, and form starch at some period of their lives. Animals, on the contrary, seem never to form starch. 5. Like the simplest animals, the simplest plants are vesicles, or vesicular threads; and the most complex plants may be regarded as indefinite multiples of such vesicles arranged in definite forms. 6. They are composed of TISSUE, out of which the elementary organs are constructed. 7. When first formed, tissue consists of a substance called cellulose, chemically composed of C24 H20 O10*; but its chemical nature is rapidly altered by the addition of azotized and other matters, and especially by an increase in the relative proportion of carbon. 8. It is a hygrometrical substance, possessing adhesiveness, elasticity, extensibility, irritability, and vitality. 9. Its adhesiveness enables the elementary organs to grow together readily when in contact. 10. Its elasticity permits it to bend and recover, or to stretch and contract itself; the former a property essential to plants in consequence of their exposure to atmospheric disturbances, from which their want of locomotion prevents their escape; the latter demanded by the emptying and * Payen. filling processes, which are incessantly in action in the elementary organs while growing. 11. Its extensibility enables it to enlarge as new matter is added to it, and to receive the fluids or gases absorbed from without. 12. Its irritability renders it susceptible of the influence of light, heat, and similar external forces. 13. Its hygrometrical quality causes it to absorb water greedily when presented to it, an essential condition of vegetable life. 14. Its vitality keeps all these qualities in play, enables plants to digest and assimilate their food, and their various organs to perform their manifold functions. Nothing can more strongly mark the ignorance which some modern chemists betray of the facts of vegetable life than their denial of vitality, and reference of every phenomenon to chemical action. If they are right, the motions of fluids, the construction of tissues, the decomposition of matter and its combination in new forms, with the thousand other circumstances of vegetable growth, should go on as well in brute as in organized matter, provided the chemical proportions are maintained. 15. Its various forms are held together by an organic mucus, cut of which the tissue itself is generated. This mucus has received the name of intercellular substance, and also of cambium when it is exuded by the parts of an already organized plant. An objection may be taken chemically to this view, but it seems to be physiologically correct. 16. Tissue occurs in the form of the cellular, the woody, the vascular, the pitted, and the laticiferous, the different modifications of which constitute the ELEMENTARY ORGANS. |