(c) Study of cross section to show cells and air spaces.
Demonstration.—Reaction of leaves to light.
Demonstration.—Light necessary to starch making.
Demonstration.—Air necessary to starch making.
Demonstration.—Oxygen a by-product of starch making.
Apple twigs split to show the course of colored water up the stem.
What becomes of the Water taken in by the Roots?—We have seen that more than pure water has been absorbed through the root hairs into the roots. What becomes of this water and the other substances that have been absorbed? This question may be partly answered by the following experiments.
Passage of Fluids up the Stem.—If any young growing shoots (young seedlings of corn or pea, or the older stems of garden balsam, touch-me-not, or sunflower) are placed in red ink (eosin), and left in the sun for a few hours, the red ink will be found to have passed up the stem. If such stems were examined carefully, it would be seen that the colored fluid is confined to collections of woody tubes immediately under the inner bark. Water evidently rises in that part of the stem we call the wood.
