Page:Scientific Memoirs, Vol. 1 (1837).djvu/247

Rh account more a whole in itself, hence we know why the plant is from necessity more closely connected with the organism of the earth than the animal; considered in which point of view, the principal peculiarities of vegetable organization are capable of a general explanation.

As the first consequence of the above fundamental peculiarity, we have to consider the division of the plant according to the direction of the two principal properties of the terrestrial organism, that is, in its tendency to inward unity (gravitation), and in its relation to the higher natural bodies (light). In this point of view, the plant must be regarded as consisting of two parts, the terrestrial and the aërial, the former consisting of the roots and stem, the latter of the leaves and flowers. From the division, or dualism, thus characterizing the plant, there follows also as a second consequence the want of internal unity in the formation of the plant in its relation to space. Moreover, while we see the animal endowed with different systems of organization, the one for absorption, assimilation, and secretion [Stoffwechsel], the other for sensation and motion, and the first system inclosed within the second in the form of intestines; the plant, on the contrary, wants the intestines properly so called, and possesses nothing to correspond with the absorbing and assimilating intestines of the animal, but that which we call the root; so that while the animal, as a unity in relation to space, exists one half within the other, the plant, on the contrary, as a duality in relation to space, appears one half upon the other. Hence we may moreover infer the original homogeneity of both halves; and this circumstance renders the reversion of their functions possible, so that the branch is converted into a root, and the root into branch, leaves, flowers, &c., as is proved by experiment. A third consequence is, that as the union of two points appears as a line, the line is the archetype of the plant; while, on the contrary, (as we shall show hereafter,) the globular form is the archetype of the animal body. The root, being subject to the law of gravitation, strikes downward toward the centre of the earth; the stem, the leaves, and the flowers, on the contrary, follow the light, and rise in the opposite direction, so that the whole represents a perpendicular line. The experiments instituted by Count Buquoi, in order to ascertain the constancy of these directions under unusual external circumstances, are in this respect well worthy of attention. Seeds were put into a layer of mould lying loose at the top and bottom ; but, though placed closer to the lower surface, instead of growing out of this, they pierced through the far stiffer part of the layer, so as to grow out of its surface. Plants which were set upside down in a flowerpot always bent their flower-stem around the edge of the pot, and grew upwards. A fourth consequence of that fundamental property of the plant is its