Plant Life on the Farm

Front Cover
Orange Judd, 1885 - Plant physiology - 132 pages
 

What people are saying - Write a review

We haven't found any reviews in the usual places.

Other editions - View all

Common terms and phrases

Popular passages

Page 57 - It is hardly an exaggeration to say that the tip of the radicle thus endowed, and having the power of directing the movements of the adjoining parts, acts like the brain of one of the lower animals...
Page 56 - We believe that there is no structure in plants more wonderful, as far as its functions are concerned, than the tip of the radicle. If the tip be lightly pressed or burnt or cut, it transmits an influence to the upper adjoining part, causing it to bend away from the affected side...
Page 57 - ... towards the centre of gravity. In almost every case we can clearly perceive the final purpose or advantage of the several movements. Two or perhaps more of the exciting causes often act simultaneously on the tip, and one conquers the other, no doubt, in accordance with its importance for the life of the plant.
Page 7 - ISo one will dispute his title to our gratitude ; but at the same time it must not be overlooked that the claims of him who can make one grow where none at all existed before, are even greater, because the difficulties to be overcome are more formidable, for where one exists already it is relatively easy to bring about its increase.
Page 57 - ... in accordance with its importance for the life of the plant. The course pursued by the radicle in penetrating the ground must be determined by the tip; hence it has acquired such diverse kinds of sensitiveness. It is hardly an exaggeration to say that the tip of the radicle, thus endowed, and having the power...
Page 49 - The growing part does not therefore act like a nail when hammered into a board, but more like a wedge of wood, which, whilst slowly driven into a crevice, continually expands at the same time by the absorption of water ; and a wedge thus acting will split even a mass of rock.
Page 57 - ... more surprising, the tip can distinguish between a slightly harder and softer object, by which it is simultaneously pressed on opposite sides. If, however, the radicle is pressed by a similar object a little above the tip, the pressed part does not transmit any influence to the more distant parts, but bends abruptly towards the object. If the tip perceives the air to be moister on one side than on the other, it likewise transmits the influence to the upper adjoining part, which bends towards...
Page 56 - By continually moving his head from side to side, or circumnutating, he will feel any stone or other obstacle, as well as any difference in the hardness of the soil, and he will turn from that side. If the earth is damper on one than on the other side, he will turn thither as to better hunting ground.
Page 56 - ... which is perhaps only the indirect result of the radicles being highly sensitive to other stimuli, is of any service to the plant. The direction which the apex takes at each successive period of the growth of a root, ultimately 'determines its whole course ; it is therefore highly important that the apex should pursue from the first the most advantageous direction ; and we can thus understand why sensitiveness to geotropism, to contact and to moisture, all reside in the tip, and why the tip determines...
Page 7 - That he deserves best of his country, who can make two blades of grass grow where only one grew before...

Bibliographic information