The latest in this series-collections is not so long on known names -- Leiber, Pohl, Davidson, Kornbluth being the most familiar -- and the 15 inclusions are made up, mostly, of short pieces. There are two stories of humans inhabited by ""colonies"" which have definite effects on their lives: the possibility of aging backwards is found in two others; there are a few with a humorous twist and more than a few based on worlds apart. Fanciful but not always fabulous.