HH: "Anthony Cheetham, both editor and friend, wrote that he needed stories on scientific themes that could be both used in a boy's science magazine, then later in an anthology ... I was interested and agreed, and decided to write a story about evolution. No shortage of material there. But the challenge was to organise it as a work of fiction, presented in an interesting yet simple manner for younger readers - and still write a story to capture the older reader when eventually the stories were anthologised ... Here it is, a work of fiction that perhaps tells you more about evolution than you care to know." Best of Harry Harrison).


  • Young Scientist, 1970

  • Science Against Man, edited by Anthony Cheetham. New York: Avon Books, December 1970, pbk, p.175-185.

  • Science Against Man, edited by Anthony Cheetham. London: Macdonald, 1971, hbk.

  • School and Society Through Science Fiction, edited by Joseph D. Olander and Martin H. Greenberg. New York: Rand McNally, 1974, hbk.

  • The Best of Harry Harrison, June 1976.

  • The Science Fictional Dinosaur, edited by Robert Silverberg, Charles G. Waugh and Martin H. Greenberg. New York: Avon, 1982, pbk.

  • as: "Trädet som Ständigt Förgrenar Sig" in Aschkelons Gator [The Best of Harry Harrison]. 1985. [Swedish].

  • 50 in 50, July 2001.