The Staff of Life suddenly and disconcertingly sprouted wings —and mankind had to eat crow! Illustrated by WOOD AS a blisteringly hot but guaranteed weather-controlled future summer day dawned on the Mississippi Valley, the walking mills of Puffy Products ("Spike to Loaf in One Operation!") began to tread delicately on their centipede legs across the wheat fields of Kansas. The walking mills resembled fat metal serpents, rather larger than those Chinese paper dragons animated by files of men in