
“I love fools' experiments. I am always making them.”
recollection http://darwin-online.org.uk/content/frameset?itemID=F2113&viewtype=text&pageseq=7 by E. Ray Lankester, from his essay "Charles Robert Darwin" in C.D. Warner, editor, Library of the World's Best Literature: Ancient and Modern (R.S. Peale & J.A. Hill, New York, 1896) volume 2, pages 4835-4393, at page 4391
Other letters, notebooks, journal articles, recollected statements