Three American Indian women in the wild west are about to give birth. One is lying on
a buffalo skin; one is lying on a moose skin; and one is lying on a hippopotamus skin. The first
woman gives birth to a boy. The second gives birth to a girl. And the third gives birth to a boy
and a girl. And this proves . . . the squaw of the hide of the hippopotamus is equal to the sum
of the squaws of the other two hides