The back of this Spider stereograph reads:
Mrs. Spider is waiting for her dinner. A fat fly may get caught in her web. A hard shake or jar tells her that her dinner has come. When an insect gets caught the spider rushes to it. She wraps the insect in a band of a silk. She does this by turning the insect over and over while she spins. Then she takes her catch to the center of the web. She sucks the insect’s blood and throws away the hard parts of its body.
If an insect breaks her web, Mrs. Spider spins a new one. Under her body at the tip are three pairs of little knobs. They are called spinnerets. Some of the spinnerets make a thread covered with glue. Can you see the tiny glue drops? Mrs. Spider can also make thread without glue. The threads that go out from the center have no glue on them. The threads that go round and round have glue on them. The spider knows just which threads to walk on. She will not get her feet caught.
The spider lays about five hundred eggs. She puts them safely in a little silken egg sac. In spring only a few young spiders come out. What do you think these spiders have done? They have eaten all their brothers and sisters.
—Keystone Vision Co.