. Cyclopedia of farm crops. Farm produce; Agriculture. j^ Fig. 28. Parts of a young plant, r, root- hairs: ft, hypo- cotyle, between the and the root: c, seed - leaves or cotyledons : I, true Fig. 29. Cross-section of a root, as it grows in the soil, show- ing the of the root-hairs (tIi) to the soil particles (s/>) and the air spaces (a): this soil is represented as con- taining the amount of water compatible with good plant-growth, water-supply is abundant, especially in the presence of sunlight, the guard-cells absorb water and ex- pand. The
. Cyclopedia of farm crops. Farm produce; Agriculture. j^ Fig. 28. Parts of a young plant, r, root- hairs: ft, hypo- cotyle, between the and the root: c, seed - leaves or cotyledons : I, true Fig. 29. Cross-section of a root, as it grows in the soil, show- ing the of the root-hairs (tIi) to the soil particles (s/>) and the air spaces (a): this soil is represented as con- taining the amount of water compatible with good plant-growth, water-supply is abundant, especially in the presence of sunlight, the guard-cells absorb water and ex- pand. The causes the walls that bound the pore or stomate to curve away from each other, thus causing the stomate to open. This is due to the fact that these inner walls are thicker than the outer walls. The effect is the same as would be produced on a rubber tube by thickening one side by cement- ing an extra strip of rubber on it. If such a tube be closed at one end while air or water is pumped in at the other, it will bend so that the thickened side becomes concave. The absorption of the water by the guard-cells is aided in sunlight by the action of the chloro- phyll grains which they contain ; these produce sugar, which aids the cell in taking up water from the other cells of the epidermis that have no chloro- phyll grains. When, therefore, the water-supply is sufficient, and especially when sunlight, temperature and. 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 Bailey, L. H. (Liberty Hyde), 1858-1954, ed. New York, The Macmillan company
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectagriculture, bookyear
