Structural Botany : Introductory. ^ ^ , j|, 



BOTANY, the study of Plant-life, as the autotrophic organisms of the world. 

 Autotrophic as implying life which works solely in terms of physical energy and 

 chemical material in the form of gases, water, and inorganic salts ; hence distinguished 

 from heterotrophic life (mainly animal) ; the latter being dependent on carbohydrate 

 and proteid material previously synthesized by plant-life. The plant normally utilizes 

 the simplest materials, as H 2 O, CO 2 , and a few salts dissolved in water, working in 

 terms of direct solar energy. Heterotrophic plants as Bacteria, Fungi, and a few 

 parasites among higher plants, are equally secondary in origin and mechanism. 



A vast subject dealing with the structure, mode of life, methods of reproduction 

 and improvement of the race, as also its progressive evolution in past time ; ranging 

 from minute forms as Bacteria (I/A) to the vegetation of the sea_and fresh-water, 

 forms of prairie and forest-land, as also cultivated plants including organisms ex- 

 ploited by the human race, as plants grown for food (cereals and fruit-trees), decorative 

 effect (florists' flowers), timber, textile, and other economic products. 



Botany in the original sense means fodder or herbage, and the science is 

 historically based on Herbs, as used in magic and medicine (Herbalism), cf. Herbalists 

 from Dioscorides (A. D. 77) to Fuchsius (1542): scientific botany as the scheduling 

 and identification of Herbs, evolved by necessity from Herbalism to Bauhin (1623) 

 and Morison of Oxford (1680); from the latter passing on to Systematy, or classifi- 

 cation by academic 'systems', culminating in Linnaeus (1735-53) and the Genera 

 Plantarum of Hooker and Bentham (1862-83). 



Other aspects as anatomy and physiology, the former dealing with minute structure, 

 the latter with the mechanism of living processes, metabolism as including anabolism 

 and katabolism, the mechanism of irritability, as response to stimulus of changing 

 environment, reproduction, asexual and sexual, heredity, variations, and the relations 

 of the individual to the race. 



Anatomy, dependent on the development of the microscope, dates to Nehemiah 

 Grew (1670-80), cf. his large volume with the first plant-sections and drawings of 

 tissues. All conceptions of plant-structure necessarily based on Land-Plants, in more 

 immediate association, taking common objects first; e.g. a piece of stick, seed, as 

 a bean, fruit, as an apple ; all show phenomena of cellular organization. ' Cell ' 

 from Robert Hooke (1667), from resemblance of a section of cork (cf. bottle-cork, 

 cut dry, low power, reflected light, tangential section) to honey-comb. Hence Cell 

 Theory of nineteenth century ; all higher organisms being constructed in terms of 

 cell-units, as living protoplasts building the tissues ; many die and give derivative 

 tissues of secondary significance, e. g. skeletal and mechanical in the aggregated 

 soma. 



Cell-Mechanism : In the history of the word ' cell ' was restricted to the con- 

 spicuous wall or chamber, characteristic of plant-tissues, rather than animal : only 

 later were the contents recognized as essentially living, as by Von Mohl (1846), and 

 termed Protoplasm : a colloidal albuminous fluid state (sol), coagulated to gel-state 

 on death, containing over 90 % water (more than milk), the actually living substance 

 of all plants and animals ; apparently evolved originally in sea-water, and auto- 

 synthetic, from ions of H', O", N'", C iv , P v , S vi , together with other elements found 

 associated, as Ca", Mg", K', Na', Cl', Fe'". Mainly of proteid-organization, as 

 investigated dead, giving compounds involving CHOH and CHNH 2 groups, &c., in 

 indefinitely complex series. ' Killed ' by heat-coagulation at about 50 C., and by 

 strong chemical solutions (' fixing reagents ') : essentially a non-molecular complex 

 of indefinite chemical action and reaction. 



A central tract of individualized nature, suspended in the general cytoplasm (in 

 both plant and animal), for metabolism and reproductive processes of more complex 

 organization, distinguished as the Nucleus; identified by Robert Brown (1833), 

 and discussed in detail in cytology. 



Plant Tissues, so named by Grew from the similarity of sections to lace-work, 

 are based on typical cells of average dimensions and details, about 50 //, diam., 

 (commonly ranging from 10-100 /t or more): spherical under action of surface- 

 tension when left to grow freely ; but usually aggregated in close contact, with or 

 without intercellular spaces; hence appearing in sections as circles (when free), 



