"What are those?" a little girl asked her sister.

"Watermelons," the bigger one said.

"I thought melons grew in gardens."

"Somebody must have thrown one here last year," the big girl said.  "Maybe one fell off the back of a truck.  Maybe a kid threw a seed.  Maybe the rain carried it here from somewhere else."

"Can we eat it?" the little girl asked.

"No, it's not grown.  It's only the size of a peach."