E.—s

68

classes, and try to account for their forms: (a) Thick, fleshy leaves; (b) leaves protected by means of spikes; (c) hairy leaves, or leaves covered with scales; (d) early and mature leaves of plants which show marked differences; (c) lop-sided leaves. (3.) Look for leaves which are modified so as to act as climbing-organs. (4.) Relation of foliage-leaves to absorbent roots: Observe during rain, or while watering with a can, the direction taken by the water falling on various plants. Where practicable, examine the roots also. Trace the course of small shot poured over plants. Examine leaf-stalks of rhubarb, beetroot, violet, &c, for grooves to convey moisture to root. Structure of Leaves: —-(5.) Veins of leaves: Try to procure " skeleton " leaves from the heaps of decaying leaves in damp places. (6.) Boil some stiff leaves for fifteen minutes in a solution of caustic potash—-1 part of potash by weight to 20 of water. Then place the leaves in a dish of water, and gently brush away the soft parts with a camels-hair brush. (7.) Compare the arrangement of veins in mono- and di-cotyledonous plants. Microscopic Structure of Leaf: —(8.) Strip off a portion of the epidermis on the under-side of a lily, hyacinth, or daffodil leaf, mount in water, and examine under the microscope for stomata. Examine the skin of the upper side of the leaf in the same way, and compare the number of pores. (9.) Cut a thin section of a leaf, and examine for grains of chlorophyll. Functions of Lea res: —(1.0.) Transpiration : Enclose a straight leaf, still attached to the plant, in a test-tube, and close the end of the tube with a split cork without injuring the leaf. Notice that moisture collects inside the tube. (11.) Place against the upper and lower surfaces of a leaf a sheet of filter-paper which has been dipped in cobalt-chloride and dried. Notice which piece of paper changes colour first. (Note: Cobalt-chloride always turns pink in the presence of moisture.) (12.) Cover two tumblers containing water with pieces of card. Through holes in the cards pass the cut ends of leafy shoots, so that they dip into the water. Block the holes with wax, and cover the shoots with tumblers. Now place one set in the light in a window, and the other in a dull situation, anil observe which of the upper tumblers becomes bedewed more rapidly. (13.) The breathing of plants: Place in a wide-mouthed bottle a handful of tips of leafyshoots, with a little moisture to keep them fresh.. Put away in the dark for about six hours, and then test with lime-water for carbonic dioxide. (14.) Repeat the last experiment, placing the jar in bright sunlight, and test again for carbonic dioxide. (15.) Inhalation of carbonic dioxide and exhalation of oxygen by leaves : Place some watercress-leaves (a) in water, through which carbonic dioxide has bubbled, in a dark place; (6) as in (a), but in bright sunlight; (c) in previously boiled water in bright sunlight. Collect the gas given off in (b) by means of a funnel and test-tube, and then test with a glowing splinter. Always be sure that no bubbles of air are entrapped amongst the watercress before commencing the experiment. Formation of Starch in Lea res: —(l 6.) Early in the morning gather some leaves (e.g., nasturtium or fuchsia), and test them for starch as follows: (i) Dip into boiling water; (ii) soak in hot alcohol to remove chlorophyll; (iii) place in a solution of iodine. After the sun has shone for a few hours gather more leaves from the same plants, ami test again. A greenish-brown stain will denote the presence of starch. (17.) Cover a portion of a leaf attached to a plant with black paper, sticking-plaster, or cork on both sides, overnight or early in the morning. When the sun has shone brightly on the plant for some hours, ninove the leaf and test for starch as in the last experiment. (18.) Test a variegated geranium or white and green leaf for starch, after the sun has shone on it for a considerable time. (19.) hate in the afternoon of a bright day examine llie stomata of a leaf under a fairly high power of the microscope, and observe the starch-granules in the guard-cells. Run a drop of iodine under the cover, and watch the effect on the starch-grains. (20.) Rub into a paste with a little water a number of nasturtium or pea leaves gathered during the night, and add this liquid to a thin starch paste. Keep warm, and after a few hours test for starch ami sugar. Protection afforded by Scale Leaves: —(2l.) Examine buds of different plants, also the conns of the crocus and gladiolus, the tubers of the Jerusalem artichoke, and the rhizomes of the Solomon's seal, and observe the way in which they are protected by scale leaves. Effect of Light on Leaves: —(22.) Leave a pot containing a young nastur-tium-plant for a few hours at some distance from a window, and then observe the position of the leaves. Notice the effect of light on the leaves of plants placed in a, window. Leaf - sleep: — (23.) Note the night position of leaves of the clover' and wood-sorrel, and compare with the day position. Experiments with FLOWERS and Fruits.—(l.) Examine as many as possible of the following flowers—tulip, lilies, buttercup, wallflower, anemone, primrose, fuchsia, geranium, pea, cucumber. pumpkin, marrow, willow, pine—also flowers of any native trees within reach. Look for the sepals, petals, stamens, pistil, and ovary in the specimens examined. Note which plants have the pistil and stamens in the same flower, and which in separate blossoms. Try to discover as many trees as possible which have the male blossoms on one tree and the female on another. (2.) Examine the flowers of wheat, barley, maize, oats, and grasses of various kinds, noting the pistils, stamens, and the scaly structures which take the place of petals. (3.) Dissect and examine composite flowers, such as'the sunflower,'daisy, groundsel, cornflower, &o. Distinguish between the showy portion designed for advertising purposes and the less conspicuous part which contains the essential organs. Pollination and Fertilisation of Flowers: —(4.) Examine pollen-grains of various flowers under a lens or microscope, and note their forms. (5.) Make a 3-per-cent., 5-per-cent., and 10-per-cent. solution of cane-sugar. Place some in separate watch-glasses, anil shake into them various kinds of pollen-grains, cover, and allow them to remain in the dark in a warm room. Place them under a microscope after twelve or eighteen hours, noting whether pollen-tubes have been produced; or crush the mature stigmas of some lilies, place the material in a watch-glass, and sprinkle pollengrains in the glass, proceeding as above. (6.) Tie up in paper bags two pistillate flowers of a cucumber, marrow, or pumpkin before they reach maturity. When the blossoms are ready, gently touch the stigma of one with a ripe anther from a staminate blossom, so that some pollen is deposited, and then replace the bag. Notice which flower produces ripe fruit, (7.) AVithering of blossoms after fertilisation : Observe a flower-head of clover, and notice the change that takes place