Some minor alterations made to text.

Published in New Worlds 1956, published by Nova Publications; also published in No Future in It by John Brunner, published by Gollancz 1962; also published in Yet More Penguin Science e Fiction edited by Brian W. Aldiss, published by Penguin 1964; also published in Science Fiction edited by S.H. Burton, published by Longman 1967; also published in The Penguin Science Fiction Omnibus edited by Brian W. Aldiss, published by Penguin 1973.