▁Neb ula ▁Science ▁F iction . ▁ ▁At ▁the ▁end ▁of ▁ 1 9 5 5 ▁Campbell ▁decided ▁to ▁give ▁up ▁editing ▁in ▁favour ▁of ▁his ▁scientific ▁career ▁as ▁a ▁research ▁chem ist . ▁He ▁was ▁replaced ▁from ▁the ▁February ▁ 1 9 5 6 ▁issue ▁by ▁E . C . ▁T ub b , ▁who ▁remained ▁editor ▁to ▁the ▁end ▁of ▁the ▁magazine ' s ▁life . ▁T ub b ▁had ▁contributed ▁a ▁great ▁deal ▁of ▁material ▁to ▁the ▁magazine ▁under ▁various ▁pseud onym s , ▁often ▁amount ing ▁to ▁more ▁than ▁half ▁of ▁an ▁issue ' s ▁fiction , ▁and ▁he ▁later ▁re called ▁that ▁Campbell ' s ▁way ▁of ▁h iring ▁him ▁as ▁editor ▁was ▁to ▁say ▁to ▁him , ▁" As ▁you ' re ▁pract ically ▁writing ▁it , ▁you ▁may ▁as ▁well ▁edit ▁it ." ▁ ▁The ▁quality ▁of ▁material ▁submitted ▁to ▁T ub b ▁was ▁" d read ful ", ▁in ▁the ▁words ▁of ▁sf ▁historian ▁Michael ▁Ash ley , ▁and ▁included ▁many ▁stories ▁that ▁had ▁previously ▁been ▁rejected ▁by ▁Campbell : ▁he ▁was ▁able ▁to ▁recognize ▁these ▁because ▁Campbell ▁had ▁kept ▁a ▁log ▁of ▁all ▁subm issions . ▁One ▁story ▁was ▁rejected ▁that ▁had ▁been ▁pl ag iar ized ▁from ▁one ▁that ▁had ▁appeared ▁twelve ▁years ▁earlier ▁in ▁Ast ounding ▁Science ▁F iction . ▁T ub b ' s ▁overall ▁accept ance ▁rate ▁was ▁about ▁one ▁in ▁twenty - five ▁subm issions . ▁As ▁a ▁result , ▁he ▁found ▁it ▁difficult ▁to ▁keep ▁standards ▁up ,