Handbook of Nature-Study · Lesson CCI · Topic 29: The apple tree
201. The apple
Goal: Your child can describe an apple inside and out, find the five seed cells, and show by experiment why bruised apples rot.
You'll need
- 3 or 4 apples, including two of the same kind and one of another kind
- A knife (for an adult) and a cutting board
- A clean pin
- A hand lens (magnifying glass)
- A nature notebook and a pencil (colored pencils if you have them)
What's in the book
The lesson has a leading thought and twelve observations on the shape, skin, stem, cavity and blossom end, two experiments on rot, and the inside of the apple cut both ways: pulp, core-line, carpels and seeds.
The lesson, step by step
The leading thought
The apple is a nutritious fruit, wholesome and easily digested. The varieties of apple differ in shape, size, color, texture and flavor.
Outside
Sketch the shape of your apple. Is it almost spherical, or flattened, or long and egg-shaped, or with unequal tapering sides?
Examine the blossom end, or basin. What is its shape? Can you find within it the remnants of the calyx-lobes, the stamens and the pistils of the flower?
Two rot experiments
Set these up today and check them over the next week.
Take three apples of equal soundness and peel one of them; place them on a shelf. Place one of the unpeeled apples against the peeled one, and the other a little distance from it.
For the second experiment, an adult pricks your initials into a sound apple with a pin that was first pushed into a rotting one. Watch where the rot begins.
Cut it lengthwise
An adult cuts one apple from stem to blossom end.
Is the flesh immediately surrounding the core separated from the rest of the pulp by a line more or less distinct? This is called the core-line
Taste the pulp: crisp or mealy, sweet or sour?
Cut it across
Cut an apple transversely across the middle. In what shape are the seed-cells arranged in the center?
Can you see, between the core-lines and the skin, faint little dots? Count, and tell how they are arranged in relation to the star formed by the core.
Look at the seeds, but don't chew them.
Compare two kinds
Cut an apple of a different variety across too. Are the stars the same? The color, smell and taste? Hold a little "apple exhibit" and score each for size, shape, color, flavor and texture, as the book suggests.
Nature notebook
Draw both cut faces of the apple. Label skin, pulp, core-line, carpels and seeds. Later, record what happened in the rot experiments.
Afterwards
Check the rot experiments every day for a week and draw what you see.
Answers to the book's problems
The cross-cut shows a five-pointed star of five seed cells (carpels), with ten little dots in a ring around it (the ends of the fibers that run from stem to blossom end). The peeled apple rots first, and the touching apple starts to rot where it touches. The pricked apple rots along the pin marks. Lesson: handle fruit gently and store it without bruises, keeping bad ones away from good ones.
Worked out for this site from the scan. If a number in your copy differs, trust the book.