Page:Scientific Memoirs, Vol. 1 (1837).djvu/251

Rh mushrooms, ferns, &c., produce their seeds immediately without the aid of the male stamina, and this circumstance accords with their texture, which is merely composed of cellular tissue. On the other hand, the male stamina, containing a generating life-imparting principle, that is, the operation of light, come nearer to animal nature. This view is in perfect accordance with the power of motion which is often to be observed in these parts, as well as with the very probable hypothesis, that the cause of the scent and of the colour of flowers may be traced to the elements of the male pollen, which is contained in their leaves. We have already stated that the seed itself being an indifference emanating from this highest polarity, contains the most concentrated image of the bud. As it has thus within itself in idea the whole organism of the plant, it is capable of reproducing in reality the whole plant out of itself.

Proceeding from this short survey of the principal phænomena of the development of plants to a further examination of their active manifestation of life, we shall find that even in this respect the vegetable kingdom, as a part of universal life, is connected with inorganic nature. It has been already observed that the life of the plant consists chiefly in the formation of its organs; whence it follows, that its most essential and fundamental activity manifests itself in the process of assimilation and secretion, as well as in the circulation of the sap, which is nothing but a repetition of the chemical attraction and repulsion observed in unorganized matter. But since the circulation of the sap is not effected by any independent peculiar organ of circulation, (such, for instance, as a kind of heart,) we must suppose this movement to be, like the ebbing and flowing of the tides, the effect of a certain attraction, partly originating in the structure of the plant, and partly in its external relations; unless we should prefer ascribing it entirely to the motion of fluids in capillary vessels, that is, in other words, to the laws of capillary attraction. But the laws of capillarity have surely but a limited influence in this case: capillarity may indeed enable us to explain the phænomenon of the rising of fluids, but not their progressive motion, and still less the flowing off of the sap when the plant is cut or injured; because a capillary tube never can overflow, and that for the very cause which makes fluids ascend, namely, their adhesion to the inner surface of the vessel. Hence, although capillary attraction has some share in the circulation of the plant, it is evident that this depends upon some higher cause. It has been already shown that the polarity of the plant between root and flower, which depends on the elementary polarity between gravitation and light, is also visible in the relation of the functions of both those parts, the root being particularly adapted to attraction and absorption, but less fit for secretion, and the