{21} "Voyages of the Adventure and Beagle," iii. p. 237. {22} "Luck, or Cunning, as the main means of Organic Modification?" (Longmans), pp. 179, 180. {23} Journals of the Proceedings of the Linnean Society (Zoology, vol. iii.), 1859, p. 61. {24} "Darwinism" (Macmillan, 1889), p. 129. {25} Longmans, 1890, p. 376. {26} See Nature, March 6, 1890. {27} "Origin of Species," sixth edition, 1888, vol. i. p. 168. {28} "Origin of Species," sixth edition, 1888, vol. ii. p. 261. {29} Mr. J. T. Cunningham, of the Marine Biological Laboratory, Plymouth, has called my attention to the fact that I have ascribed to Professor Ray Lankester a criticism on Mr. Wallace's remarks upon the eyes of certain fiat-fish, which Professor Ray Lankester was, in reality, only adopting--with full acknowledgment--from Mr. Cunningham. Mr. Cunningham has left it to me whether to correct my omission publicly or not, but he would so plainly prefer my doing so that I consider myself bound to insert this note. Curiously enough I find that in my book "Evolution Old and New," I gave what Lamarck actually said upon the eyes of flat-fish, and having been led to return to the subject, I may as well quote his words. He wrote:- "Need--always occasioned by the circumstances in which an animal is placed, and followed by sustained efforts at gratification--can not only modify an organ--that is to say, augment or reduce it--but can change its position when the case requires its removal.