"Eighty-eight cubic metres of card-index," said Mr. Foster with relish, as they entered.

"Containing all the relevant information," added the Director.

"Brought up to date every morning."

"And co-ordinated every afternoon."

"On the basis of which they make their calculations."

"So many individuals, of such and such quality," said Mr. Foster.

"Distributed in such and such quantities."

"The optimum Decanting Rate at any given moment."

"Unforeseen wastages promptly made good."

"Promptly," repeated Mr. Foster. "If you knew the amount of overtime I had to put in after the last Japanese earthquake!" He laughed goodhumouredly and shook his head.

"The Predestinators send in their figures to the Fertilizers."

"Who give them the embryos they ask for."

"And the bottles come in here to be predestined in detail."

"After which they are sent down to the Embryo Store."

"Where we now proceed ourselves."

And opening a door Mr. Foster led the way down a staircase into the basement.

The temperature was still tropical. They descended into a thickening twilight. Two doors and a passage with a double turn insured the cellar against any possible infiltration of the day.

"Embryos are like photograph film," said Mr. Foster waggishly, as he pushed open the second door. "They can only stand red light."

And in effect the sultry darkness into which the students now followed him was visible and crimson, like the darkness of closed eyes on a summer's afternoon. The bulging flanks of row on receding row and tier above tier of bottles glinted with innumerable rubies, and among the rubies moved the dim red spectres of men and women with purple eyes and all the symptoms of lupus. The hum and rattle of machinery faintly stirred the air.