Lesson CX

Cobwebs

Leading thought—The cobwebs which are found in the corners of ceilings and in other dark places in our houses, are made by the house spider which spins its web in these situations for the purpose of catching insects.

Method—The pupils should have under observation a cobweb in a corner of a room, preferably with a spider in it.

Observations—1. Is the web in a sheet or is it a mass of crisscrossed, tangled threads? How are the threads held in place?

2. What is the purpose of this web? Where does the spider hide? Describe its den.

3. If a fly becomes tangled in a web, describe the action of the spider. Does the spider eat all of the fly? What does it do with the remains?

4. If the spider is frightened, what does it do? Where does the silken thread come from, and how does its source differ from the source of the silken thread spun by caterpillars?

5. Imprison a spider under a tumbler or in a vial, and look at it very carefully. How many legs has it? How does the spider differ from insects in this respect? How many sections are there to the body? How does the spider differ from insects in this respect?

6. Look closely at the head. Can you see the hooked jaws, or fangs? Can you see the palpi on each side of the jaws? Where are the spider’s eyes? How many pairs has it?

When the tangled cobweb pulls
The cornflower’s cap awry,
And the lilies tall lean over the wall
To bow to the butterfly
It is July.

—Susan Hartley Swett.