“So what does the female look like?” she said. “Obviously you can’t have something like that without some place to put it in. You need a garage to park the car.”
The lower oviduct (the equivalent of the vagina in birds) is typically a simple tube. But when Dr. Brennan dissected some female ducks, she discovered they had a radically different anatomy. “There were all these weird structures, these pockets and spirals,” she said.
Somehow, generations of biologists had never noticed this anatomy before.