"Peril of the Blue World" in Planet Stories, Winter 1942 "The Canal Builders" in Astounding, January 1945 "Heritage" (novella) in Astounding, June 1947 "The Dead-Star Rover" in Planet Stories, Winter 1949 "Strange Exodus" in Planet Stories, Fall 1950 "The Rotifers" in if, March 1953 "Axolotl" (also published as "Deep Space") in F&SF, January 1954 "Heirs Apparent" (novella) in F&SF, June 1954 "Pyramid" (novella) in Astounding, July 1954 "Single Combat" in F&SF, January 1955 "Junior" in Galaxy, January 1956 "Grandma's Lie Soap" in Fantastic Universe, February 1956