Elphinstone Dayrell, Folk Stories from Southern Nigeria…
“ But why does the king give half his kingdom to the tortoise? When an adventurer in fairy tales wins the hand of the king's heiress, he usually gets half the kingdom. The tortoise is said to have been "the wisest of all men and animals." Why? He merely did not kill his daughter. But there is no temptation to kill daughters in a country where they are valuable assets, and command high bride-prices. In the Australian tribes, the bride-price is simply another girl. A man swops his sister to another man for the other man's sister, or for any girl of whose hand the other man has the disposal. ”
