Ontario Teachers' Manuals: Nature Study Part 39

OBSERVATIONS

I

The general shape, and the suitability of the shape for swimming.

The surface of the body and the protection it affords. Note the scales and the slime, the latter a protection against the growth of fungi, etc.

The gills--two openings behind the flaps at the rear of the head. The colours, and their value in concealing the fish. The dark upper surface makes it inconspicuous from above; the light under surface blends with the shadow and dims it.

The divisions of the body--head, trunk, and tail.

Movements of the fish and the part that the various fins play in these movements.

Note that the broad tail fin is the most useful fin for locomotion, the others act as balancers or as brakes, or for causing currents of water near the gills. Observe the movements of the pair of fins nearest the gills, the movements of the mouth, and the currents of water entering the mouth and pa.s.sing through the gill slits. When a fish is kept in a very small quant.i.ty of water, observe the effect produced on the movements of the mouth and gill flaps. What are the uses of these movements? The pupils will thus discover the nature of the respiration of the fish. Why do fish die if many are kept in a jar of water?

II

By supplying various foods learn what kinds are preferred. Find in the actions or habits of the living fish evidences of a sense of smell, of sight, of hearing, and of taste.

Nearly all the following points of detailed study can be observed from the living fish: shape; size; tongue; teeth; gill slits leading from the mouth to the gills; nostrils, number and position; eyes, absence of eyelids; fins, size, build; the arrangement of the scales.

PROBLEMS

Why does the fish require a large mouth?

How are the eyes protected? Compare the shape of the eye with the shape of the eye of a land animal.

Why are there no openings from the surface directly into the ears? Show the suitability of the fins as organs of locomotion in water.

REFERENCES

Silc.o.x and Stevenson: _Modern Nature Study_

Nash: _Fishes of Ontario_ (from Department of Education, free)

Kellogg: _Elementary Zoology_

CHAPTER XII

FORM IV

AUTUMN

GARDEN WORK

The regular work of cultivation of garden and experimental plots should be carefully attended to. Pupils in this Form should be able to do all kinds of garden work with a good deal of proficiency. The work of selecting the best flowers for seed production should be continued.

These should be used for planting in the school garden and in home gardens as well. This part of the work might be left to the girls. The boys should be encouraged to take up the systematic selection of seed grain. To get good seed to start with, two methods may be used:

1. Decide upon the kind of grain to be selected and choose from one of the best fields a hundred of the best heads--those that are vigorous, clean, free from rust or s.m.u.t, and standing up straight. When the heads are dried a little, sh.e.l.l the grain off them and preserve it in a jar in a cold, dry place until spring.

2. Take a quart of oats and pick it carefully, keeping only the largest and most plump kernels. Keep this for spring planting. At the same time, a sample of the poorer grains should be kept for comparison. A regular system of selection should be followed from year to year, taking enough of the largest, brightest, and most compact heads from the plot each autumn to sow a plot of equal size the next spring. After the selection of heads has been made, the remainder of the crop may be harvested, and the grain from this known as general crop from hand-selected seed of the first, second, third year, etc. If the value per acre is required, the plots should be made of a certain size easy to compute, such as one rod square or one rod by two rods. (10-1/2 ft. by 21 ft. is about 1/200 acre.) Samples of each crop should be kept in uniform bottles and labelled; for example--"From selected heads of 1911". The yield per acre in the plot from which the selected heads came should also be noted.

These will be interesting for purposes of comparison and for testing duration of vitality later. If the same amount of grain is used in planting a plot each time, the change in bushels per acre may be ascertained and also in pounds per bushel. Some of the boys in this Form may wish to continue this work of improvement by selection and, if so, they should communicate with the Secretary of the Canadian Seed Growers'

a.s.sociation, Canadian Building, Ottawa, and receive full instructions to enable them to carry on their work practically as well as scientifically.

HERBACEOUS PERENNIALS FROM SEED

The teacher should encourage the growing of herbaceous perennials for the purpose of beautifying the school grounds. Many plants may be started from seed at the school and given to the pupils for home planting. These plants require but little attention and provide excellent bloom in gardens and home grounds from early in spring before annuals are in bloom, on into the autumn. A list of the best varieties will be found in Circular 13, on _Elementary Agriculture and Horticulture_, a copy of which should be in every school. The seed plot should be fertilized and prepared in the usual way, and the seeds planted before the first of September. They may be started in June also, in which case they make more growth before winter. The plot should be well fertilized with thoroughly rotted manure and, if the soil is very dry, the plot should be well watered the day before the seeds are planted. The seeds are usually quite small and should be covered very lightly. The plot should be protected from the hot sun by means of cheese-cloth tacked on a frame. The plants should be watered twice a week in dry weather. In the late autumn, when the ground freezes, the plot should be covered with leaves or straw and some boards, which should be removed when the frost comes out in the spring.

DECIDUOUS TREES

Before the pupils of this Form leave school they should be able to recognize, by name as well as by sight, all of the species of trees found in their vicinity. To this end the teacher should help them to prepare an inventory of species of trees, shrubs, and vines of the vicinity. They should learn to distinguish the different species of maples, elms, birches, etc. A named collection of leaves helps materially in doing this. The influence of environment upon the growth and shape of trees and how trees adapt themselves to the conditions in which they live is a most interesting and profitable study, demanding careful observation, reflection, and judgment.

REFERENCES

Muldrew: _Sylvan Ontario._ Briggs.

Keeler: _Our Native Trees._ Scribners' Sons. $2.00.

TREES IN RELATION TO THEIR ENVIRONMENT

Consider the influences at work and their effect under the following heads:

1. CHARACTER OF THE SOIL AND SUBSOIL.--It may be gravelly, pure sand, sandy loam, clay or clay loam, muck or humus, shallow or rocky, and the subsoil may be sand, clay or hard clay with stones (hard-pan). Notice what species are most common in each kind of soil.

2. WATER SUPPLY.--What species are found naturally in moist ravines or along the margins of rivers and lakes, in bogs or swamps, on dry, sandy plains, or rocky hillsides. Consider also the rainfall.

3. EXPOSURE TO SUNLIGHT.--Account for the lack of symmetry in the shapes of trees. Branches grow only where their leaves can get the light.

Account for the pith in many tree stems not being in the geometric centre. Account for the rapid growth in height made by young trees in the woods. Their light supply is chiefly from above, and they stretch up toward it as rapidly as possible. Dim light causes rapid growth at the expense, however, of strength of tissue, but as these young trees are protected in the woods from the strain of wind storms, their slimness and lack of toughness is a benefit rather than a hindrance to them.

Also, the limbs near the ground die off while the trees are still young and small, giving us the clear timber tree, free from large knots, tall and straight. Make further application of this principle of light in relation to the planting of trees for shade and for wood or lumber.

Account for the large size of the leaves of young trees in the dimly lighted woods as compared with the leaves of older trees. The principle of rapid growth in dim light is seen here also. It will be noticed that the large leaves of the young trees are more thin, soft, and flexible.

4. WIND.--Observe the tops of tall trees that have always been exposed to a strong prevailing wind as, for instance, those growing on the tops of hills or the eastern sh.o.r.e of a lake which has a prevailing west wind. The tops lean in the direction in which the prevailing wind blows.

Does strong wind help or hinder the growth of a tree? Examples of stunted trees on wind swept hills or sh.o.r.es readily show this. It will be seen also that the higher branches are poorest on the side most exposed to the wind.

5. SUITABILITY OF THE SPECIES TO THE CLIMATE.--Observe that some trees retain their leaves much later in the autumn than do others. The beech, hickory, red oak, and chestnut are good examples. These are on the northern extreme of their territory of growth. The tree best suited to a rigorous climate is the one that finishes its work early in the autumn and has all its tissues well matured before cold weather sets in.

Examples: maple, elm, birch, and willow.

FRUITS

EXCURSION TO A WELL-KEPT ORCHARD

If the teacher can arrange to take the pupils to see a well-kept orchard about the time of the apple harvest, it will help to arouse interest in the study of fruits. The trees, as well as the fruit, frequently show distinguishing marks whereby they may be identified. Have the pupils notice the following points: general shape of tree, colour of bark, shape of leaf, method of cultivation, fertilizing, pruning and grafting, spraying and its need, orchard pests, method of picking and packing apples in barrels and boxes for market.