Ontario Teachers' Manuals: Nature Study

by Ontario. Department of Education

OUTLINE OF A CLASS-ROOM LESSON ON THE WHITE PINE

Inferences.—If possible, each pupil is supplied with a small branch of the white pine and the teacher with a larger branch which can easily be seen by all the pupils. Before proceeding to examine the specimens, give the pupils a chance to tell what they now know about the white pine, and thus review the lesson taken out-of-doors. Then ask a few questions bearing upon their own observations, such as: What was the soil like where you found the pine tree growing? (They are found most commonly on light, sandy soil.) Did you notice any difference between the shapes of the pines in the deep woods and the pines in the open fields? Did you notice any dead limbs on those in the woods? Why did they die? The pupils may conclude that branches whose leaves cannot get the sunlight must die. Show that this causes knots in the lumber and exhibit samples. This explains also why the trees of the forest have such tall stems without branches for a long distance up from the ground. They get the light only from above and seem to strive with the surrounding trees to reach it. If we want trees to grow tall, how should we plant them? (Close together) What would such trees be good for? (Making timber or lumber) If we want trees to grow low and have thick and bushy tops, how should we plant them? (Far apart) What would such trees be good for? (Their shade and their beauty) Good shade trees should be thirty to forty feet apart.

Ask the pupils if they have ever been near a pine tree when a gentle breeze was blowing, and have them tell the cause of the sound that they heard. They may decide that the shape and size of the leaves caused the sound when the wind was blowing through the tree top. Have them examine the branches in order to discover the following points:

Leaves.—These are in bunches of five, two to three inches long, three-cornered, and with little teeth pointing toward the tip, light green near the tip of the bough (young leaves) and darker further down (older leaves); age of a leaf the same as the age of the wood it grows on, therefore some leaves are one year, some two, and a few three years old. No leaves on four-year-old wood, therefore the leaves fall off the white pine the third year. Ask pupils to try to find out by observation when the leaves fall off the pines. Note the fragrance of the leaves, and that they are sometimes put into "pine" cushions, also, how slippery they are to walk on.

Buds.—These are found at the tips of the branches, one large one in the centre and several smaller ones grouped around it. Note their reddish-brown colour and that they are made up of scales overlapping and covered with gum which keeps out the rain, thus protecting the little growing tip inside. When buds grow, they become little twigs with leaves on. Find where the buds were a year ago. Notice the light colour of the twigs that grow during the present season and the darker colour of the twigs of the previous year. Where were the buds two years ago? What did the centre bud become? (A continuation of the stem) What did the other buds, called lateral buds, become? (New branches) Compare the growth made in different years.

Notice also how white the wood of the twigs is—the probable reason for calling it "white pine".

Cones.—Note the length and shape of the cones and how the seeds are placed in them inside the large scales. Get some of the seeds and note the wing-like attachment. Take the wing off a seed and drop it from a height at the same instant with one that has its wing attached. Note the whirling motion and infer what purpose the wing serves in scattering seed. Taste the kernel of a pine seed and discover why squirrels are fond of them. Burn a pine cone.

Find out what birds like to live in this tree. What has been noticed about them and their nests?

Have the pupils keep the seeds until the following spring by putting them in a box of dry sand and setting them in a cold place. They should then plant them in a corner where they can be partly shaded when the sun is bright. Plant them about half an inch deep and keep them watered if the weather is dry during the first summer.

Note.—The cones drop their seeds from high up in the tree so that the wind can carry the seeds long distances. The cones usually stay on the trees for a couple of years after they lose their seeds.