3. Examine grains of wheat, barley, oats, and rye, as harvested. In which of these are the pales present? What is the “beard” of barley?
4. Make a collection of “seeds” of various grasses, and write down the characters by which they may be distinguished from each other.
5. What are the commonest weeds you have seen in corn fields? Do the corn and the weeds flower at the same time or not? Is the time of flowering an advantage (a) to the weeds, (b) to the farmer?
6. In what important respects do wind-fertilized flowers differ from insect-fertilized flowers? Give examples of each. (1898)
CHAPTER VIII.
COMMON FOREST TREES.
30. THE OAK FAMILY.
1. The oak.—(a) Habits of growth.—Examine an oak tree growing in an exposed situation. What is its approximate height? Estimate the diameter of the trunk at (a) the ground level, (b) at heights of 1, 2, 3, 4, etc., feet. At what height do the principal boughs come off? About what angle do the boughs make with the trunk? Are they straight, evenly curved, or zig-zag? Contrast in these respects an oak growing in a plantation. Try to account for the differences observed.
(b) The bark.—Examine the barks in oaks of various ages. Do the ridges and furrows caused by the splitting of the bark form any definite pattern, or are they arranged anyhow? Find a piece which shows the pattern well, and make a drawing of it.