. How crops grow. A treatise on the chemical composition, structure, and life of the plant, for all students of agriculture ... Agricultural chemistry; Growth (Plants). EEPKODtrCTIVE ORGANS OP PLANTS. 295 volvulus. The cut represents a magnified section length- wise through the short pistil; a, is the stigma or summit are pollen tubes. of the pistil; 5, are grains of pollen ; that have penetrated into the seed- vessel which forms the base of the pistil; one has entered the mouth of the rudimentary seed, g, and reached the embryo sack, e, within which it causes the development of a germ; d, rep
. How crops grow. A treatise on the chemical composition, structure, and life of the plant, for all students of agriculture ... Agricultural chemistry; Growth (Plants). EEPKODtrCTIVE ORGANS OP PLANTS. 295 volvulus. The cut represents a magnified section length- wise through the short pistil; a, is the stigma or summit are pollen tubes. of the pistil; 5, are grains of pollen ; that have penetrated into the seed- vessel which forms the base of the pistil; one has entered the mouth of the rudimentary seed, g, and reached the embryo sack, e, within which it causes the development of a germ; d, represents t!5e interior wall of the seed-vessel; h, the base of the seed and its attachment to the seed-vessel. Darwin has shown that certain plants, which have pistils and stamens in the same flower, are incapable of self-fertilization, and depend upon in- sects to carry pollen to their stigmas. Such are many Orchids. Artificial Fecundation has been proposed by Hooibrenk, in Belgium, as a means of increasing the yield of certain crops. Hooi- brenk's plan of agitating the heads of grain at the time when the pollen is ripe, in order to ensure its distribution, which is done by two men traversing the field carrying a rope between them so as to lightly brush over the heads, appears to have been found very useful in some cases, though in many trials no good effects have followed its application. "We must therefore conclude that agitation by the winds and the good offices of insects commonly render artificial assistance in the fecundating process en- tirely superfluous. Hybridizing.—As the union of the sexes of diflTerent kinds of animals sometimes results in the birth of a hybriJ, so among plants, the ovules of one kind may be fertilized by the pollen of another, and the seed thus developed, in its growth, produces a hybrid plant. In both the animal Fig 63 Digitized by Microsoft®. Please note that these images are extracted from scanned page images that may have been digitall
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectagricul, bookyear1868
