1082. In the liber is the main seat of vegetable activity. For it is soft cellular tissue with open intercellular passages, wherein the sap can move.
1083. Now as every fascicle of spiral fibres is surrounded by liber, such a fascicle must be regarded as a whole plant. A plant consists accordingly of as many plants, as it has or can have tracheal fasciculi. Every plant is a trunk of infinitely numerous plants; for every one can contain infinitely numerous tracheal fascicles. One plant is a whole vegetable world. (Ed. 1st, 1810. § 1065.)
3. CELLULAR-SYSTEM, BARK.
1084. No spiral vessels lie upon the surface of the plant, for where they originate, there the liber forms around them, and this is consequently the External. The surface of plants is therefore necessarily environed by liber, notwithstanding the greater influence of the light. The cellular tissue upon the surface of plants is, however, less rich in sap than the liber around the tracheal fasciculi, because it is too rapidly evaporated and dried up by the immediate contact of the air, light and heat. The surface of the plant is too strongly oxydized by the air, and therefore the cells harden. The sap also decomposes too rapidly and becomes rigid, so that an irregular formation only can proceed from it. The external, more inactive, or irregularly wood-converted layer of cells, is the Bark.
1085. The plant has thus likewise three anatomical systems, which are nothing new, but only the repetition or rather vagination of the three tissues; alburnum and cambium are only transitional, not special formations.
III. Organs of the Vegetable Trunk.—Members.
1086. Organs are separated parts of the body, and combinations of single tissues and systems, and are consequently a Whole in Singulars. There are, however, no uniform combinations; but one or the other system asserts its preponderance and imparts the character.
1087. In conformity with the developmental progress of the whole of nature, namely, that of always separating further its chaotically mingled parts, individualizing and yet forming them with the others into a whole, vegetation cannot continue stationary with the partition into bark, liber and wood, seeing that they are always circumscribed and form a body in common; but they must also sever this body itself into as many members as it has constituent parts. This severance makes its appearance in the longitudinal axis, because in this direction the antagonisms of air and light with water and earth are more powerful.
1088. Through the separation of the vegetable trunk three members only can originate; one with the preponderance of cells or of bark, one with that of vessels or of liber, and one with that of the tracheæ or of wood. The cellular tissue has been posited as vegetable trunk in the root, the vascular tissue as a special member is stalk, the tracheal tissue leaf. In this manner the trunk of the plant divides into three great divisions; more are not possible.
1089. Now the root is the perfected water-organ, because it is always fixed in water; the leaf is the perfected air-organ, because it moves in the air; the stalk is the perfected earth-organ, because it removes the mass out of water and air. Root is a heap of cells; leaf a plane of tracheæ; stalk a bundle of vessels.