1100. The perpendicular direction of the stalk is, however, as mechanically determined by gravity as the root. Paradoxical as this assertion may appear, it is still correct; for if we think of a moist globe, which is superiorly affected by air, light and heat, the upper aqueous or mucous parts are thus lighter, and necessarily ascend upwards through the pressure of the heavy or unheated parts, just as the air-bubbles in beer ascend to the surface. The light it is true can draw them somewhat sideways, chiefly because this side is more heated, more decomposed, and also undergoes a greater amount of evaporation; but the proper cause invariably resides in the ascent of the light parts between the heavy or immoveable. The stalk therefore grows upwards also in the darkness, and then indeed quite perpendicularly, because it has not been diverted by light. Were the light merely the Dirigent, it could not be comprehended, why towards the poles trees still stand tolerably perpendicular, and do not lie completely upon the earth. Were, however, the air that which determines the direction, plants could not thus have been inclined towards the sun, nor could we comprehend why the flowers and also the leaves obey the sun's course. Finally, were neither air nor light the imparters of direction, then the plant could shoot in no other direction than quite perpendicularly upwards, as is done too for the most part by the fungi. 1101. The _winding_ of the stalk appears to originate from the rotation of the sun. The next cause is probably the greater heating and decomposition that occurs upon one side. In accordance with this assumption the plants upon the northern hemisphere of the earth must wind spirally upwards from left to right, or from morning towards evening, if our gaze be directed towards the meridian, but inversely upon the southern hemisphere. But this is not the case. May we therefore conjecture that plants, twisted contrary to rule, have been transported from their native soil? 1102. The kinds of stalk follow also, without doubt, the direction of developmental stages of the vegetable trunk. There are therefore cellular stalks in the fungi, vascular stalks in the mosses, tracheal stalks in the ferns. A bark-stalk is the culm, a liber-stalk the scape, a wood-stalk probably the trunk of a palm. A root-stalk is the rhizoma, a perfect-stalk the stem, a leaf-stalk being probably the shrub. _Ramification._ 1103. The differencing, severing character of air and light must never be lost from our thoughts, nor also that at a height this character manifests itself more powerfully than on the surface of the earth, where the stem abandons its androgynous position in relation to the root. Through the constant process of differencing the tracheal fascicles of the plant may finally become so independent that they no longer stand in need of the others, and do not merely represent a particular plant, but are perfected also as such.