. Botany for secondary schools; a guide to the knowledge of the vegetation of the neighborhood. Plants. 86 FOOD ELABORATION AND RESPIRATION the cut end of the twig. This gas has been found to be largely oxygen. The water-plant gets its carbon dioxid gas from that which is dissolved in the water. A gas, as well as a solid, may be dissolved in water. Observe the bubbles on pond-scums and water-weeds on bright day. 181. Starch is present in the green leaves that have been ex- posed to sunlight; but in the dark no starch can be formed from carbon dioxid and water. Apply iodin to the leaf from whic
. Botany for secondary schools; a guide to the knowledge of the vegetation of the neighborhood. Plants. 86 FOOD ELABORATION AND RESPIRATION the cut end of the twig. This gas has been found to be largely oxygen. The water-plant gets its carbon dioxid gas from that which is dissolved in the water. A gas, as well as a solid, may be dissolved in water. Observe the bubbles on pond-scums and water-weeds on bright day. 181. Starch is present in the green leaves that have been ex- posed to sunlight; but in the dark no starch can be formed from carbon dioxid and water. Apply iodin to the leaf from which the chlorophyll was dissolved in a previous experiment (174). Note that the leaf is colored purplish brown throughout. Starch gives a blue coloration with iodin. The leaf contains starch (76). Secure a leaf from a plant that has been in the darkness for about two days. Dissolve the chlorophyll, as before, and attempt to stain this leaf with iodin. No purplish brown color is produced. 182. Plants or parts of plants that have developed no chlorophyll can form no starch. Secure a variegated leaf of coleus, ribbon-grass, geranium, or of any plant showing both white and green areas. On a day of bright sunshine, test one of these leaves by the alcohol and iodin method for the presence of starch. Observe that the parts devoid of green color have formed no starch. However, after starch has once been formed in the leaves, it may be changed into soluble substances and removed to be again converted into starch in other parts of the living 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. New York, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectplants, bookyear1913
