The only cow in a small town in Scotland stopped giving milk. However, the towns folk found they could buy a cow in Wales quite cheaply. So they brought the cow from Wales and it was wonderful, produced lots of milk every day and everyone was happy.
Then they bought a bull to mate with the cow to get more cows, so they'd never have to worry about their milk supply again. They put the bull in the pasture with the cow but whenever the bull tried to mount the cow, the cow would move away. No matter what approach the bull tried, the cow would move away from the bull and he was never able to do the deed.
The people were very upset and decided to go the Vet who was very wise, tell him what was happening and ask his advice. "Whenever the bull tries to mount our cow, she moves away. If he approaches from the back, she moves forward," they said. "When he approaches her from the front, she backs off. If he attempts from the one side, she walks away to the other side."
The Vet rubbed his chin thoughtfully and pondered before asking, "Did you by any chance, buy this cow in Wales?" The people were dumbfounded, since no one had ever mentioned that they had brought the cow over from Wales.
"You are truly a wise Vet!" they said. "How did you know we got this cow from Wales?"
With a distant look in his eye, the Vet replies, "My wife is from Wales."
