. Plants and their ways in South Africa. Botany; Botany. 22 Plants and their Ways in South Africa Ex. 7. Cover the outside of the glass germinator or of a funnel with several thicknesses of flannel. Fasten seeds which have just germinated by means of a narrow strip of flannel to the upper edge of the glass. Keep the flannel moist, and the roots will follow the inclined face of the germinator instead of growing vertically. The flannel must not be too moist, or the roots will turn from it. Ex. 8. Growth Curvatures caused by Light—Place the germinator in a box lighted at one end. Notice the seedl
. Plants and their ways in South Africa. Botany; Botany. 22 Plants and their Ways in South Africa Ex. 7. Cover the outside of the glass germinator or of a funnel with several thicknesses of flannel. Fasten seeds which have just germinated by means of a narrow strip of flannel to the upper edge of the glass. Keep the flannel moist, and the roots will follow the inclined face of the germinator instead of growing vertically. The flannel must not be too moist, or the roots will turn from it. Ex. 8. Growth Curvatures caused by Light—Place the germinator in a box lighted at one end. Notice the seedlings in a day or so. The stems will bend towards the lighted end. Will the roots show a turning away from the light ? The seedlings of sunflower are very sensitive to light. Place some m a bright light and cover with black paper, leaving an opening at one side. Notice how the cotyledons turn their flat surfaces to the light. As soon as the next pair of leaves appear, reverse the position, so that they turn directly away from the light. Will they turn back ? Try the experiment with other seedlings. Fig. 29 shows a young castor-oil plant. All the leaves, in- cluding the cotyledons, have turned toward the window. The. Fig. 30.—The plant in this pot grew on the north side of a large rock. The portion beside the j^iot grew on tile south side in the shade. Stalks (f>etio/es) of the cotyledons have curved so as to bring the surface of the rot)'le(lons into a favourable lighl 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 Stoneman, Bertha. London, New York, Longmans, Green
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1915
