On Rack 10 rows of next generation's chemical workers were being trained in the toleration of lead, caustic soda, tar, chlorine. The first of a batch of two hundred and fifty embryonic rocket-plane engineers was just passing the eleven hundred metre mark on Rack 3. A special mechanism kept their containers in constant rotation. "To improve their sense of balance," Mr. Foster explained. "Doing repairs on the outside of a rocket in mid-air is a ticklish job. We slacken off the circulation when they're right way up, so that they're half starved, and double the flow of surrogate when they're upside down. They learn to associate topsy-turvydom with well-being; in fact, they're only truly happy when they're standing on their heads.

"And now," Mr. Foster went on, "I'd like to show you some very interesting conditioning for Alpha Plus Intellectuals. We have a big batch of them on Rack 5. First Gallery level," he called to two boys who had started to go down to the ground floor.

"They're round about Metre 900," he explained. "You can't really do any useful intellectual conditioning till the foetuses have lost their tails. Follow me."

But the Director had looked at his watch. "Ten to three," he said. "No time for the intellectual embryos, I'm afraid. We must go up to the Nurseries before the children have finished their afternoon sleep."

Mr. Foster was disappointed. "At least one glance at the Decanting Room," he pleaded.

"Very well then." The Director smiled indulgently. "Just one glance."

Chapter Two

Mr. Foster was left in the Decanting Room. The D.H.C. and his students stepped into the nearest lift and were carried up to the fifth floor.

INFANT NURSERIES. NEO-PAVLOVIAN CONDITIONING ROOMS, announced the notice board.

The Director opened a door. They were in a large bare room, very bright and sunny; for the whole of the southern wall was a single window.