“
An egg is not likely to grow on its own," said the crow crossly.
"She's right," said Edward. "I've never seen a grown-up egg."
"The egg doesn't grow!" cried the bird. "It's what's inside that grows."
"Then why don't you sit on what's inside?" Avon asked.
"Because there's a shell."
"What makes you so sure there's something inside?" asked Edward.
"It's always been that way!" insisted the crow.
”
”
Avi (A Beginning, a Muddle, and an End: The Right Way to Write Writing)