"Out in the middle of" joke

Out in the middle of darkest Africa there was a White Missionary
living with a tribe of black natives.
On day the big chief comes along and calls the Missionary into
his hut, where he was sharpening his big axe. He explains to the white
man that his daughter has just given birth to a white baby, and
that since he's the only white man for thousands of miles, he will
be the main course that night.
"Now just hang on a minute, give me a chance to explain chief,"
says the Missionary. "You're jumping to conclusions here. Let me
tell you a story. See all those white sheep out in the field and
how there's one black one amongst them."
"OK!" says the Chief," You say nothing, I say nothing!"