Ontario Teachers' Manuals: Nature Study Part 9

Who has the twig that had the most rapid growth?

_To the teacher._--The bud at the end of the twig or its branches is called the end bud; there are two leaf scars underneath it. The buds along the sides of the stem are called side buds, the latter are smaller than the end bud. The bud situated between the stem of the leaf and the twig is in a sheltered position. This position also puts the bud close to the pantry door, for the plant food is prepared in the leaf. The leaf scars are yellowish-brown, or if they are the scars from the leaves of former years, are dark brown in colour. Each scar is shaped like a horse-shoe and tiny dots are found in the position that the horse-shoe nails would have. Even before the leaf falls, a layer of corklike substance has formed over the scar. This layer is a protection against the entrance of frost and rain and germs of fungi and it also prevents the loss of sap from the scar. The tiny oval pores, each as large as the point of a needle, are the breathing pores of the twig. The bands of rings are the scars of the scales of the end buds of successive years.

This latter fact can be discovered when the bud is opening.

REVIEW LESSON

The review lesson should consist of a review of the points taken up in the lessons that were based on the horse-chestnut twig, supplemented by the examination of the twigs of elm, apple, or lilac.

LESSON ON BUDS

~Materials.~--Twigs and buds of horse-chestnut, one for each pupil. An opening bud. (A bud or a twig placed in water in a warm room will develop rapidly.)

~Lesson.~--Distribute specimens, and review the positions of the buds.

Pupils examine the buds and tell all they can about them. They describe the colour, shape, and size of the buds, and also their gummy and scalelike covering.

Of what use are the gum and scales? Of what use is the brown colour of the bud?

They next find out what is inside the little brown house. They open the buds and try to identify the contents. There will be some uncertainty as to the meaning of the contents. Leave this over till spring.

_To the teacher._--The brown colour of the bud makes it an absorbent of sunlight, and also serves as a protection from observation by the sharp eyes of bud-eating birds. The gummy scales are waterproof, and the scales, by spreading open gradually, cause the waterproof property to be retained even after the bud has grown quite large. The inner part of the bud is composed of two, four, or six tiny leaves folded up and supported on a short bit of stem. Some of the buds have, in addition to leaves, a tiny young flower cl.u.s.ter. All of these things are densely covered with white down. The down is the fur coat to protect the tender parts from the cold.

REVIEW LESSON

Review the lesson on buds, but subst.i.tute buds of the lilac or apple for the horse-chestnut buds of the original lesson.

CORRELATIONS

The observational study of the buds and twigs is a good preparation for busy work in art and manual training, and the pupils may be a.s.signed exercises, such as charcoal drawing of a horse-chestnut twig, paper cutting of a lilac twig and buds, clay or plasticine modelling of twigs and buds.

For oral and written language exercises, enlarge the vocabulary of the pupils by requiring sentences containing the words--scales, twigs, buds, protection, terminal, lateral, leaf stalk, blade, etc.

LEAVES

Leaves, because of their abundance and the ease with which they may be obtained, are valuable for Nature Study work. It is possible to arouse the interest of even young children in the study of leaves, but care must be taken not to make the observation work too minute and the descriptions too technical for the primary cla.s.ses.

FIELD EXERCISES

An excursion to the school grounds or to some neighbouring park will suffice to bring the pupils into direct contact with the following plants: a maple tree, a Boston ivy (or other climbing vine), a nasturtium, a geranium.

Ask the pupils to find out where and how leaves are placed on each of these plants, that is, whether they are on the inner parts of the branches of the tree or out at the ends of the branches. Do the leaves overlap one another or does each make room for its neighbours? Are the leaves spread out flat or curled up? What holds the leaves out straight and flat? What do the leaves need to make them green and healthy?

Are the leaves placed in the right way, and are they of the right form to get these things?

_To the teacher._--The leaves of the plants named are quite noticeably so placed on the plants, have such relations to one another, and are of such outline that they present the greatest possible surface to the _air_ and _sunshine_ and _rain_. The leaf stalk and midrib and veins are stiff and strong to keep the leaves spread out. Compare with the ribs of an umbrella. The benefit of sunshine to leaves and plants can be developed by discussing with the pupils the paleness and delicateness of plants that have been kept in a dark place, such as in a dark cellar.

They are also acquainted with the refreshing effect of rains upon leaves. The use of air to the leaves is not so easy to develop with pupils of this age, but the use of air for breathing just as boys and girls need air for breathing may be told them.

CLa.s.s-ROOM LESSON ON LEAVES

~Introduction.~--Tell me all the things that you know upon which leaves grow. On trees, bushes, flowers, plants, vegetables, etc.

Are leaves all of the same shape?

To-day we are going to learn the names of some of the shapes of leaves.

~Observations.~--Show the cla.s.s the heart-shaped leaf of catalpa or lilac, and obtain from the pupils the name _heart-shape_. Use the following types:

Maple leaf as star-shape, Gra.s.s or wheat or corn as ribbon-shape, Nasturtium or water-lily as shield-shape, Ash or rowan, as feather-shape.

~Drill.~--Pupils pick out the shape named. Pupils name the plant to which each belongs. Which shape do you think is the prettiest?

GARDEN STUDIES

If the pupils of this Form have planted and cared for garden plots of their own, they will have a greater love for the flowers or vegetables that grow in them than for any others in the garden, because they have watched their development throughout. For them such continuous observation cannot but result in a quickening of perception and a deepening of interest and appreciation.

STUDIES IN THE PUPIL'S INDIVIDUAL PLOT

What plant is the first to appear above ground? What plant is the last to appear? Describe what each plant was like when it first appeared above ground. What plants grow the fastest? What effect has cold weather, warm weather, dry weather, on the growth of the plants?

What weeds grow in the plot?

Why do these weeds obstruct the growth of the other plants?

What kind of root has each weed?

Find out what kind of seeds each weed produces?

Why is each weed hard to keep out of fields?

What garden plants produce flowers?

How are the seeds protected?

Compare the seeds with those that you planted.

Select the seeds of the largest plants and finest flowers for next year's seeding.

STUDIES FROM THE GARDEN AS A WHOLE

What plants grow tallest?

What plants are most suitable for borders?

What plants are valuable for their flowers?

What plants are valuable for their edible roots, for their edible leaves, for their edible seeds?