. Botany for high schools. Botany. WORK OF ROOTS IN ABSORPTION 35 rise above the surface of the water in the bottle. Water then flows through the membrane into the sugar solution, but the sugar and the dye do not pass through the membrane to any great extent unless left for a long time. 58. Turgor in the plant cell is sometimes illustrated in the following way. A medium-sized vial is filled wnth ^ p'^ a saturated solution of sugar. Over the j^^^^ open end a piece of bladder membrane ^^^^ which has been thoroughly soaked is securely tied in such a way as to exclude ^ the air. The vial is then i
. Botany for high schools. Botany. WORK OF ROOTS IN ABSORPTION 35 rise above the surface of the water in the bottle. Water then flows through the membrane into the sugar solution, but the sugar and the dye do not pass through the membrane to any great extent unless left for a long time. 58. Turgor in the plant cell is sometimes illustrated in the following way. A medium-sized vial is filled wnth ^ p'^ a saturated solution of sugar. Over the j^^^^ open end a piece of bladder membrane ^^^^ which has been thoroughly soaked is securely tied in such a way as to exclude ^ the air. The vial is then immersed in Same as Fig. , ,39 after needle a vessel or water and allowed to stand is removed, for a day or two. It is then taken from the vessel of water. The membrane is arched upward as if by a pressure within. If the membrane is pricked with a needle, and the instrument quickly withdraw^n, a stream of water spurts out because of the inside pressure. 59. How the root hairs get water from the soil.—Most land plants get their water and food solutions from soil which is moist or sometimes even appears dry. How can they take up water from moist soil or from soil which is so dry that no water can be pumped from it? The soil is composed of very finely pulverized rock, in the form of minute angular grains. Mixed with these fine grains is more or less matter of an organic nature, the disintegrated remains of plants. When soil is not saturated with water, the water present is in the form of a thin film which surrounds the soil particles. The soil particles touch each other, but because of their form there are spaces between them just as there are spaces between the stones in a pile. The film of water which surrounds the soil particles meets and joins with adjacent soil particles at their points of contact, thus making a continuous film for a great extent through the soil, reaching down to the ground water below. The spaces between the soil particles are filled with air, which is ver
Size: 1574px × 1587px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
