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elongates itself when it is thus most excited. Whence one of these grows upward in quest of its adapted object, and the other downward*.” Were this account better verified by experiment than it is, it only shifts the contrivance. It does not disprove the contrivance; it only removes it a little further back. Who, to use our author's own language, “adapted the objects?” Who gave such a quality to these connate parts, as to be susceptible of different “stimulation;” as to be “excited” each only by its own element, and precisely by that, which the success of the vegetation requires? I say, “which the success of the vegetation requires :” for, the toil of the husbandman would have been in vain; his laborious and expensive preparation of the ground in vain; if the event must, after all, depend upon the position in which the scattered seed was sown. Not one seed out of a hundred would fall in a right direction. - Our second observation is upon a general property of climbing plants, which is strictly mechanical. In these plants, from each knot or joint, or, as botanists call it, axilla of the plant, issue, close to each other, two
* Darwin's Phytologia, p. 144.
shoots: one bearing the flower and fruit; the other, drawn out into a wire, a long, tapering, spiral tendril, that twists itself round any thing which lies within its reach. Considering, that in this class two purposes are to be provided for (and together), fructification and support, the fruitage of the plant, and the sustentation of the stalk, what means could be used more effectual, or, as I have said, more mechanical, than what this structure presents to our eyes? Why, or how, without a view to this double purpose, do two shoots, of such different and appropriate forms, spring from the same joint, from contiguous points of the same stalk? It never happens thus in robust plants, or in trees. “We see not (says Ray) so much as one tree, or shrub, or herb, that hath a firm and strong stem, and that is able to mount up and stand alone without assistance, furnished with these tendrils.” Make only so simple a comparison as that between a pea and a bean. Why does the pea put forth tendrils, the bean not; but because the stalk of the
pea cannot support itself, the stalk of the bean can P. We may add also, as a circumstance not to be overlooked, that in the peatribe, these clasps do not make their appearance till they are wanted; till the plant has
grown to a height to stand in need of support. This word “support” suggests to us a reflection upon a property of grasses, of corn, and canes. The hollow stems of these classes of plants are set, at certain intervals, with joints. These joints are not found in the trunks of trees, or in the solid stalks of plants. There may be other uses of these joints; but the fact is, and it appears to be, at least, one purpose designed by them, that they corroborate the stem; which, by its length and hollowness, would otherwise be too liable to break or bend. Grasses are Nature's care. With these she clothes the earth; with these she sustains its inhabitants. Cattle feed upon their leaves; birds upon their smaller seeds; men upon the larger: for, few readers need be told that the plants, which produce our bread-corn, belong to this class. In those tribes, which are more generally considered as grasses, their extraordinary means and powers of preservation and increase, their hardiness, their almost unconquerable disposition to spread, their faculties of reviviscence, coincide with the intention of nature concerning them. They thrive under a treatment by which
other plants are destroyed. The more their leaves are consumed, the more their roots increase. The more they are trampled upon, the thicker they grow. Many of the seemingly dry and dead leaves of grasses revive, and renew their verdure, in the spring. In lofty mountains, where the summer heats are not sufficient to ripen the seeds, grasses abound, which are viviparous, and consequently able to propagate themselves without seed. It is an observation, likewise, which has often been made, that herbivorous animals attach themselves to the leaves of grasses; and, if at liberty in their pastures to range and choose, leave untouched the straws which support the flowers”. The GENERAL properties of vegetable nature, or properties common to large portions of that kingdom, are almost all which the compass of our argument allows to bring forward. It is impossible to follow plants into their several species. We may be allowed, however, to single out three or four of these species as worthy of a particular notice, either by some singular mechanism, or by some peculiar provision, or by both. I. In Dr. Darwin's Botanic Garden (1.395, note), is the following account of the vallis* Withering, Bot. Arr. vol. i. p. 28, ed. 2d.
neria, as it has been observed in the river Rhone.—“They have roots at the bottom of the Rhone. The flowers of the female plant float on the surface of the water, and are furnished with an elastic, spiral stalk, which extends or contracts as the water rises or falls; this rise or fall, from the torrents which flow into the river, often amounting to many feet in a few hours. The flowers of the male plant are produced under water; and, as soon as the fecundating farina is mature, they separate themselves from the plant; rise to the surface; and are wafted by the air, or borne by the currents, to the female flowers.” Our attention in this narrative will be directed to two particulars: first, to the mechanism, the “elastic, spiral stalk,” which lengthens or contracts itself according as the water rises or falls; secondly, to the provision which is made for bringing the male flower, which is produced under water, to the female flower which floats upon the surface. II. My second example I take from Withering's Arrangement, vol. ii. p. 209. ed. 3. “The cuscuta europaea is a parasitical plant. The seed opens, and puts forth a little spiral body, which does Not seek the earth, to take root; but climbs in a spiral direction, from