Acknowledgment is made for permission to print the following material:

 

“Guyal of Sfere,” by Jack Vance. Copyright © 1950 by Hillman Publications, Inc.; copyright renewed © 1978 by Jack Vance. First published in The Dying Earth (Hillman), 1950. Reprinted by permission of the author and the author’s agent, Ralph M. Vicinanza, Ltd.

 

“Old Hundredth,” by Brian W. Aldiss. Copyright © 1960 by Brian W. Aldiss. First published in New Worlds, November 1960. Reprinted by permission of the author.

 

“Alpha Ralpha Boulevard,” by Cordwainer Smith. Copyright © 1961 by Mercury Press, Inc; copyright © 1963 by Cordwainer Smith. First published in The Magazine of Fantasy & Science Fiction, June 1961. Reprinted by permission of the author’s estate and the agents for the estate, Scott Meredith Literary Associates, Inc., 845 Third Avenue, New York, NY 10022.

 

“Day Million,” by Frederik Pohl. Copyright © 1966 by Rogue Magazine. First published in Rogue Magazine, February 1966. Reprinted by permission of the author.

 

“Bumberboom,” by Avram Davidson. Copyright © 1966 by Mercury Press, Inc. First published in The Magazine of Fantasy & Science Fiction, December 1966. Reprinted by permission of the author’s estate and the executor of the estate, Grania Davis.

 

“Coranda,” by Keith Roberts. Copyright © 1967 by New Worlds. First published in New Worlds, January 1967. Reprinted by permission of the author and the author’s agents, The Owlswick Literary Agency.

 

“Nightwings,” by Robert Silverberg. Copyright © 1968 by Galaxy Publishing Corporation. First published (under the title “Watcher”) in Galaxy, September 1968. Reprinted by permission of the author.

 

“Pale Roses,” by Michael Moorcock. Copyright © 1974 by Michael Moorcock. First published in New Worlds 7 (Sphere, 1974). Reprinted by permission of the author and the author’s agents, Howard Morheim.

 

“Anniversary Project,” by Joe Haldeman. Copyright © 1975 by the Conde Nast Corporation. First published in Analog Science Fiction/Science Fact, October 1975. Reprinted by permission of the author.

 

“Slow Music,” by James Tiptree, Jr. Copyright © 1980 by James Tiptree, Jr. First published in Interfaces (Ace, 1980). Reprinted by permission of the author’s estate and the agents for the estate, the Virginia Kidd Literary Agency.

 

“The Map,” by Gene Wolfe. Copyright © 1984 by Gene Wolfe. First published in Light Years and Dark (Berkley, 1984). Reprinted by permission of the author and the author’s agent, The Virginia Kidd Literary Agency.

 

“Dinosaurs,” by Walter Jon Williams. Copyright © by Davis Publications, Inc. First published in Isaac Asimov’s Science Fiction Magazine, June 1987. Reprinted by permission of the author.

 

“The Death Artist,” by Alexander Jablokov. Copyright © Davis Publications, Inc. First published in Isaac Asimov’s Science Fiction Magazine, August 1990. Reprinted by permission of the author.

 

“Sister Alice,” by Robert Reed. Copyright © 1993 by Bantam Doubleday Dell Magazines. First published in Asimov’s Science Fiction, November 1993. Reprinted by permission of the author.

 

“Recording Angel,” by Paul J. McAuley. Copyright © 1995 by Paul J. McAuley. First published in New Legends (Tor Books, 1995). Reprinted by permission of the author.

 

“Genesis,” by Poul Anderson. Copyright © 1995 by Poul Anderson. First published in Far Futures (Tor Books, 1995). Reprinted by permission of the author.

 

“The Days of Solomon Gursky,” by Ian McDonald. Copyright © 1998 by Dell Magazines. First published in Asimov’s Science Fiction, June 1998. Reprinted by permission of the author.