On plot No. 5, two oz. nitrate of soda, two oz. muriate of potash, and four oz. bone meal.
On plot No. 6, use no fertilizer. Record results.
(2) Effect on different crops: Try a series of experiments similar to the above, using (a) peas instead of oats, (b) using corn, (c) using cabbage, (d) using potatoes.
FUNCTION OF PARTS OF PLANTS
This may be introduced in Form III and continued in the next Form. Already the attention of the pupils has been directed to the essential organs of the flower, namely, stamens and pistil. They have noticed the two kinds of flowers on pumpkins, corn, and many trees. They have seen that only the pistillate flowers produce fruit and seeds, and that when the staminate flowers have shed their pollen, they die. They have seen the yellow dust that the stamens contain and have seen bees laden with it as they emerge from the heart of the flower. Have them watch the bee as it enters the flower and notice how it invariably rubs some part of its pollen-covered body against the pistil. When on the moist, sticky top of the pistil, these little pollen-grains soon begin to grow, sending a delicate tube down to the bottom of the pistil to the ovary. Inside the ovary are little bodies called the ovules that are moistened by a fluid that comes from this delicate pollen tube, and at once they begin to enlarge and eventually become the seeds. The coverings surrounding them complete the true fruit.
The use of the root in supporting the plant in its normal position is apparent to every pupil. To demonstrate the firm hold it has upon the soil, have the pupils try to pull up some large plants by the roots. They will then notice the branching roots of some plants and the long conical roots of others. Compare the colour and other surface features of the root and stem. To prove its feeding power, try two plants of equal size, taking the root off one and leaving it uninjured in the other. Set them side by side in moist earth and notice which withers. Take all the leaves off a plant and keep them off for a few weeks. The plant dies if its leaves are not allowed to grow. Keep it in the dark for a long time, and it finally dies even when water and soil are supplied. The leaves, therefore, are essential and require sunlight in doing their work. Their complete work will be considered later.
HOW THE PLANT GETS ITS FOOD FROM THE SOIL
When seeds germinate, the lower end of the caulicle, which becomes the root, bears large numbers of root-hairs. Inside the root-hairs is protoplasm and cell sap. These root-hairs grow among the soil particles which lie covered over with a thin film of moisture. It is this moisture that is taken up by these root-hairs, and in it is a small amount of mineral matter in solution which helps to sustain the plant. The transmission of soil water through the delicate cell walls of these root-hairs is known as osmosis.
GERMINATION OF SOME OF THE COMMON GRAINS
Make a special study of corn, wheat, and buckwheat. Take three plates and put moist sand in each to a depth of about half an inch. Spread over this a piece of damp cloth. Put in No. 1, one hundred grains of corn; in No. 2, the same number of grains of wheat; and in No. 3, the same number of grains of buckwheat, peas, or beans. Cover each plate with another piece of damp cloth and invert another plate over each to prevent drying out. Keep in a warm room and do not allow the cloths to become dry. If one of the cloths be left hanging six or eight inches over the side of the plate and dipping into a dish of water, the whole cloth will be kept moist by capillarity. Note the following points: