Botany

(bot'ah-ne.) [ Gr.botane, an herb.] That branch of natural history which treats of plants. It is divisible into: 1. Structural B., Organography, or Vegetable Anatomy, which has reference to the parts of which plants are composed. 2. Physiological B., which has reference to the proce es carried on by living plants. 3. Systematical B., or Taxonomy, in which the relations of plants to one another are considered with a vie wto their arrangement and cla ification. Under the first the elementary organs or vegetable ti ues are studied. All plants originate in, and in their simplest state wholly consist of, minute vesicles called cells, which are formed of an elastic membrane composed of cellulose. This is a compound of carbon, hydrogen and oxygen. The ti ues composed of it, for example the pith, are termed cellular or parenchymatous. Cells are usually round or oval, but they are sometimes prismatic al, stellate, and of other shapes. The other elementary ti ue of plants is called vascular, and consists of tubes much longer than wide. These are probably elaborated out of cells. Woody fibre, or ligneous ti ue, is an instance of such tubes or elongated cells with thickened walls and pointed ends. All the ve els and channels through which fluids flow are composed of vascular ti ue variously arranged. All the organs of plants are formed out of these two ti ues. The principal parts of a plant are the RoOT, STEM, LEAVES, FLOWER, and FRUIT, q. v.- The oldest botanical work which has come down to us is that of Theophrastus, a pupil of Aristotle, who flourished in the 4th cent. B. c. His 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 W. Europe, that it was ever again studied as it had been by him. One of the earliest methodical arrangements was that ofCæsalp in us, a Roman physician attached to the court of Pope Sixtus V. This was entirely artificial; and the same may be affirmed of the several systems of Gesner, Morison, Rivinus, and Tournefort. That propounded by Tournefort was for a long time adopted by the French school, but was ultimately displaced by the attractive scheme of Linnæus, who must be looked upon as the great promulgator of the artificial method of cla ification. Linnæus divided all known plants into 24 cla es, distinguishing them according to the number or situation of the stamens, filaments, anthers, or male and female flowers in each plant. Of all the botanists of the latter half of the 18th cent., the most deserving to be mentioned in the history of the science along with the great Swede, are Bernard de Ju ieu, and his nephew, Antoine Lament de Ju ieu, who applied themselves with great earnestne to the study of the natural affinities of plants, and traced, 1789, the outlines of a natural system, which the greatest botanists since their time have not so much sought to change as to complete. Among those who have labored with great succe in this work, must be mentioned De Candolle, Fries, Endlicher, Brongniart, Meisner, Von Martius, Brown, and Lindley. In the arrangement proposed by the last-named, a cla ification adopted in the present work, the number of orders of known plants extends to 303, grouped into 56 alliances. The main divisions consist of Asexual or Flowerle plants, which include THALLOGENS and ACROGENS (q. v.); and Sexual or Flowering plants, which include RHIZOGENS, ENDOGENS, DICTYOGENS, GYMNOGENS, and EXOGENS (q.v.). [s. 108]