Lesson CLXIX

The Maize

Leading thought—The Indian corn, or maize, is a plant of much beauty and dignity. It has wonderful adaptations for the development of its seed and for resisting its arch-enemy, the wind.

Method—The study may begin in spring when the corn is planted, giving the pupils the outline for observations to be filled out in their note-books during the summer, when they have opportunities for observing the plant; or it may be studied in the autumn as a matured plant. It may be studied in the school room or in the field, or both.

Observations on the corn plant—1. Describe the central stem. How many joints, or nodes, has it? Of what use to the plant are these nodes? Are the joints nearer each other at the bottom or the top of the plant?

2. Where do the leaves come off the stem? Describe the relation of the bases of the leaves to the stem. Of what use is this to the plant?

3. Note the little growth on the leaf where it leaves the stalk. Describe how this prevents the rain from seeping down between the stalk and the clasping leaf. What danger would there be to the plant if the water could get into this narrow space?

4. What is the shape of the leaf? Describe the veins. Does the leaf tear easily across? Does it tear easily lengthwise? Of what use to the leaf is this condition?

5. Are the edges of the corn leaf straight or ruffled? How does this ruffled edge permit the leaf to turn without breaking? Describe at length the benefit the corn plant derives from having leaves which cannot be broken across and that can bend readily sidewise as well as up and down.

6. Describe the roots of the corn plant. Describe the brace-roots. Explain their use.

7. Describe all the ways in which the corn plant is strengthened against its enemy, the wind.

Observation on the ear of corn—8. Where on the corn plant are the ears borne? Are two ears borne on the same side of the stalk? Remove an ear, and see how the stalk is changed to give it room.

9. Where do the ears come off the stalk in relation to the leaves?

10. Examine the outside husks, and compare them with the green leaves. What is there to suggest that the corn-husk is a leaf changed to protect the seed? Do you think that the husk represents that portion of the leaf which clasps the stalk? Why? Describe how the inner husk differs from the outer in color and texture. Describe how this is a special protection to the growing kernels.

11. After carefully removing the husk, examine the silk and see if there is a thread for every kernel. Is there an equal amount of silk lying between every two rows? Do you know what part of the corn flower is the cornsilk? What part is the kernel?

12. How many rows of kernels are there on an ear? How many kernels in a row? How many on the whole ear? Do any of the rows disappear toward the tip of the ear? If so, do they disappear in pairs? Do you know why? Are the kernels on the tip of the ear and near the base as perfect as those along the middle? Do you know whether they will germinate as quickly and vigorously as the middle ones?

13. Study a cob with no corn on it and note if the rows of kernel-sockets are in distinct pairs. This will, perhaps show best if you break the cob across.

14. Break an ear of corn in two, and sketch the broken end showing the relation of the cob to the kernels.

15. Are there any places on the ear you are studying, where the kernels did not grow or are blasted? What happened to cause this?

16. Describe the requisites for a perfect ear of seed-corn. Why should the plant from which the seed-ear is taken be vigorous and perfect?

Observations on the growth of corn—Work for the Summer Vacation—17. How does the corn look when it first comes up? How many leaves are there in the pointed roll which first appears above the ground? How long before the central stalk appears?

18. When do the tassels first appear? What kind of flowers are the corn tassels? Describe the anthers. How many on each flower? Where do the anthers open to discharge their pollen?

19. How large are the ears when the pollen is being shed? Study an ear of corn at this period. Note that the kernel is the ovule, the silk is attached to it and is the long style extending out beyond the husks. Note that the tip, or stigma is branched.

20. What carries the pollen for the corn plant? If you have rows of popcorn and sweet corn or of sweet corn and field corn next to each other why is it that the ears will show a mixture of both kinds?

EXPERIMENT 1

Compare the growth of the corn plant with that of the pigweed. When the corn-stalk first appears above ground, tie two strings upon it, one just above a joint and one below it. Tie two strings the same distance apart on the stem of a pigweed. Measure carefully the distance between these two strings on the two plants. Two weeks later measure the distance between the strings again. What is the result?

EXPERIMENT 2

Measure the distance between two of the nodes or joints near the tip of a certain corn-stalk. Two weeks later measure this distance again and compare the two.

EXPERIMENT 3

When a stalk of corn is still green in August, bend it down and place a stick across it at about half its length. Describe how it tries to lift itself to an erect attitude after two or three weeks. Cut lengthwise across one of the nodes, beyond the point held down by the stick, and see the wedge-shaped growth within the joint which helps to raise the stalk to an upright position.

EXPERIMENT 4

During the August drought, note that the corn leaves are rolled. Give a corn plant with rolled leaves plenty of water and note what happens. Why?