. Elements of botany. Plants. MINUTE STRUCTURE OF LEAVES. 121 starch from water and carbonic acid gas. Parasites, like the dodder, which are destitute of green coloring-matter, cannot do this, neither can sajjrophytes or plants which live on decaying or fermenting organic matter, animal or vegetable. Most sapropliytes, like the moulds, toadstools, and yeast, are flowerless plants of low organization, but there are a few such as the familiar Indian pipe. Fig. 100, which flourish on rotten wood or among decaying leaves, that bear flowers and seeds. 152. Detection of Starch in Leaves. — Starch ma
. Elements of botany. Plants. MINUTE STRUCTURE OF LEAVES. 121 starch from water and carbonic acid gas. Parasites, like the dodder, which are destitute of green coloring-matter, cannot do this, neither can sajjrophytes or plants which live on decaying or fermenting organic matter, animal or vegetable. Most sapropliytes, like the moulds, toadstools, and yeast, are flowerless plants of low organization, but there are a few such as the familiar Indian pipe. Fig. 100, which flourish on rotten wood or among decaying leaves, that bear flowers and seeds. 152. Detection of Starch in Leaves. — Starch may be found in abundance by microscopical examination of the green parts of growing leaves, or its presence may be shown by testing the whole leaf with iodine solution. 153. Experiment 29. Occur- rence of Starch in Nasturtium Leaves. — Boil some bean leaves or leaves of nasturtium (Tropmolum) in water for a few minutes to kill the protoplasmic contents of the cells and to soften and swell the starch-grains. Soak the leaves (after boiling) in strong alcohol for a day or two to dissolve out the chlorophyll, which would otherwise make it difficult to see the blue color of the starch test, if any were obtained. Rinse out the alcohol with plenty of water and then place the leaves for half an hour in a solution of iodine, rinse off with water and note what portions of the leaf, if any, show the presence of starch. 154. Experiment 30. Consumption of Starch in Nasturtium Leaves. — Select some healthy leaves of Tropfeolum on a plant growing vigorously indoors or, still better, in the open air. Shut off the sunlight from parts of the selected leaves (which are to be left on the plant and as little injured as may be) by pinning circular disks of cork on opposite sides of the leaf, as shown in Fig. 101. On the afternoon of the next day remove these leaves from the plant and treat as described in the pre- ceding experiment, taking especial pains to get rid of all the chlorophyll by cha
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1896
