[250] C. H. Schultz, "Sur la Circulation dans les Plantes," a prize-essay, 1839.
In the "Dictionnaire des Sciences Naturelles" (article _Animal_) we find: "If, on the one hand, animals show avidity in their search after nourishment as well as power of discrimination in the selection of it, roots of plants may, on the other hand, be observed to direct themselves towards the side where the soil contains most nourishment, nay, even to seek out the smallest crevices in rocks which may contain any food. If we twist a bough so as to make the upper surface of its leaves the under one, these leaves even will twist their stems in order to regain the position best suited for the exercise of their functions (_i.e._ so as to have the smooth side uppermost). Is it quite certain that this takes place unconsciously?"
F. J. Meyen has devoted a chapter, entitled "Of the movements and sensations of plants," to a full investigation of the subject now before us. In this he says[251]: "Not unfrequently potatoes, stored in deep, dark cellars, may be observed towards summer to shoot forth stems which invariably grow in the direction of the chinks through which the light comes into the cellar, and to continue thus growing until they at last reach the aperture which receives the light directly. In such cases potato-stalks have been known to reach a length of twenty feet; whereas under ordinary circumstances, even such as are most favourable to the growth of the potato, the stalk is seldom longer than from three to four feet. It is interesting to watch closely the course taken by a potato-stalk thus growing in darkness, in its endeavours to reach the light. It tries to do so by the shortest road, but not being firm enough to grow straight across through the air without support, it lets itself drop on to the floor, and thus creeps along the ground till it reaches the nearest wall, up which it then climbs." Even this botanist too is led by his facts to the following assertion (p. 576): "On observing the freedom of movement of _oscillatoria_ and other inferior plants, we may perhaps have no alternative but to attribute a species of _will_ to these beings."
[251] F. J. Meyen, "Neues System der Pflanzenphysiologe" (1839), vol. iii. p. 585.