Part of the confusion about sangomas and inyanga stems from the many quack healers operating throughout the country, who advertise cures for all manner of diseases, potions to increase penis size, ensure success in love or business or sometimes to ensure your enemy's downfall.

BBC: Witnessing a South African healer at work

You can find strong statistics, and useless investment signals from butter production in Bangladesh, the US population of 9 year old kids, and now, in a dramatic breakthrough, relating average penis size to GDP growth, a key measure of stock market returns around the world.

FORBES: Move up http://i.forbesimg.com t Move down

Right whales have one of the smallest brain-to-body-size ratios of any cetacean, the longest penis in the animal kingdom (averaging more than seven feet or 2.3m) and testes with a combined weight of one tonne.

ECONOMIST: The lives of whales