
“Time flies like an arrow. Fruit flies like a banana.”
No known citation to Marx. First appears unattributed in mid-1960s logic/computing texts as an example of the difficulty of machine parsing of ambiguous statements. Google Books http://books.google.co.uk/books?client=firefox-a&lr=&as_brr=0&q=%22fruit-flies%22+%22time+flies%22+banana&btnG=Search+Books&as_drrb_is=b&as_minm_is=0&as_miny_is=1900&as_maxm_is=0&as_maxy_is=1970. The Yale Book of Quotations dates the attribution to Marx to a 9 July 1982 net.jokes post on Usenet.
Misattributed