10. A school museum contains, among other things, some dandelion fluff, a dish of marrowfat peas, a few nodules of garlic, and some hawthorn berries. How could you employ these to illustrate a lesson on plant germination? (Certificate 1903)
CHAPTER X.
FERNS AND HORSETAILS.
38. FERNS.
1. The male-fern.—(a) Habit of growth.—In summer dig up a plant of the common male-fern ([Fig. 146]) and wash the soil from the roots. Make out the short, stumpy, creeping stem, covered with the hairy bases of old leaves; the slender matted roots springing from the leaf-bases; the large, compound leaves or fronds of the current year, and the coiled young leaves which have not yet expanded.
(b) The stem.—Remove the large leaves, leaf-bases, and roots from the stem, and examine it. Notice how the youngest leaves are grouped round the apex of the stem. Cut across the other end of the stem, and notice the cut ends of the conducting strands embedded in a softer ground-tissue. Cut the stem in halves lengthwise and carefully scrape away the ground-tissue of one half to see how the harder conducting strands are connected together. If you spoil this, try again on the other half, after boiling it until it is softened.
(c) The leaves.—Make a drawing of one of the expanded leaves. Notice that the leaf consists of a number of leaflets, and that these are again cut up into segments, or are at least deeply lobed. Notice the brown hairs clothing the leaf-stalk and the midrib.
Notice the crozier-like coiling of the young fronds, and make out that when they uncoil the inside of the coil becomes the upper surface of the leaf.
(d) The reproductive organs.—Examine the lower surface of full-grown fronds, and notice the brown rounded patches. Dry some leaves bearing these patches and shake them over a sheet of paper. Collect the brown dust which falls from the patches; it consists of minute grains called spores.