1092. The root, as producing mucus or infusoria, has therefore in itself the organic process of putrefaction, in so far as the origin of mucus and infusoria is a result of the putridity. It corresponds to imbibition and digestion. To this is referrible the mouldy, and as it were fetid, condition of the root. Through the process of decomposition, which it evokes in its neighbourhood, it kills its nutriment, takes possession of it, and thus originates completely, as does every first organism, out of putrefaction, out of infusoria. To the essence of the root belong therefore not merely food, but the favouring relations of decomposition, as earth and water, whereby the access of the air, as necessary to every galvanism, has not been suppressed. 1093. The earth is not merely a mechanical station for the plant, in order to give it the perpendicular direction, but it is necessary for polar excitation, whereby the decomposition is imparted. A plant placed upright in pure water, although with the roots, necessarily perishes. Darkness is at the same time the lurking-place of putrefaction, as being that which only plays its part in localities where the polarizing and dissevering influence of light is wanting. 1094. The root always passes perpendicular into the earth, on account of its greater weight due to repletion with water. In all zones therefore the root stands perpendicular to the horizon, and thus the whole plant, although this is somewhat inclined towards the sun. 1095. The developmental stages of the root pass probably parallel to the parts of the vegetable stem. a. In respect to the tissue, there are thus cellular roots, as is probably the case in the fungi, and with the fibrils of all roots; tubular or vascular roots as in the mosses, tracheal roots in the rest. b. In respect to the systems the bulbs are the cortical or bark-roots; the tubers the liber-roots; the fibres the woody-roots. c. In respect to the members of the trunk, the turnip is perhaps the genuine root, the tap-root the stalk-root, the so-called aerial roots, the leaf-roots. 2. EARTH-ORGAN.--STALK. 1096. The stalk is the idea of the whole plant, posited under the import of the organ of nutrition, of the vessels. The structure of the stalk is therefore accordant with that of the root. The anatomical systems are alike in both, bark, liber and tracheæ being in the same envelope.