. Cassell's popular gardening. Gardening. Fig. 13.—Knight's Wheel, showing the effect of growing Seeds on the surface o( a vertically rotating " Fig. 14. Effect of growing Plants on a horizontally rotating Wheel. ground, it would be liable to be doubled up in a contorted ; Above the apex, the radicle is also sensitive, but in this case the effect is to cause the radicle to bend, not away from, but towards the obstacle, so that it curls round it and gets on the other side of it. In endeavouring to give an idea of what goes on in the tip of the root, and of the way in which
. Cassell's popular gardening. Gardening. Fig. 13.—Knight's Wheel, showing the effect of growing Seeds on the surface o( a vertically rotating " Fig. 14. Effect of growing Plants on a horizontally rotating Wheel. ground, it would be liable to be doubled up in a contorted ; Above the apex, the radicle is also sensitive, but in this case the effect is to cause the radicle to bend, not away from, but towards the obstacle, so that it curls round it and gets on the other side of it. In endeavouring to give an idea of what goes on in the tip of the root, and of the way in which it is thereby en- abled to penetrate the ground, we may avail ourselves of the com- parison made by Darwin between the snout of a mole or other burrowing animal and the tip of the root. By continual movement of the head, the animal feels any stone or other obstacle, as well as differences in the degree of compact- ness of the soil, and he will turn away from the harder side to that which is softer and moister. The Caulicle.— While the radicle is pursuing its downward course provision is being made for the upraising of the seed-leaves, or "cotyledons," and of the bud or " plumule," which is des- tined to leng- then into the stem. Very frequently, but not universally, there is a little stalk interven- ing between the radicle and the seed-leaves; or it may more correctly be said that it always exists, but is sometimes so small as not readily to be visible. This stalk is the " tigeUum," or " ; It constitutes the whit>e stalk which supports the seed-leaves of Mustard and Cress, and is particularly well seen in the French Bean or in the Melon (Figs. 15, 16, 17). It may be. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Fish, David Taylor, 1824-1901. London,
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Keywords: ., bookcentury1800, bookdecade18, booksubjectgardening, bookyear1884
