(1) Sharples, Ellen. 1816. http://biologybiozine.com/images/CDSharples-lores.jpg.
(2) Richmond, George. On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. 1830.
(3) Laurence, Samuel. 1853. http://jadepricephoto.com/darwiniana/lawrence-1853.jpg
(4) Edwards, Ernest. 1866. http://www.npg.org.uk/collections/search/portrait.php?search=ap&npgno=Ax17797&eDate=&lDate=
(5) Rejlander, Oscar. 1871. http://darwin-online.org.uk/content/frameset?view&itemID=A289&pageseq=1.
(6) Ellion & Fry. 1881. http://www.flickr.com/photos/cpurrin1/2262636867/
(2) Richmond, George. On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. 1830.
(3) Laurence, Samuel. 1853. http://jadepricephoto.com/darwiniana/lawrence-1853.jpg
(4) Edwards, Ernest. 1866. http://www.npg.org.uk/collections/search/portrait.php?search=ap&npgno=Ax17797&eDate=&lDate=
(5) Rejlander, Oscar. 1871. http://darwin-online.org.uk/content/frameset?view&itemID=A289&pageseq=1.
(6) Ellion & Fry. 1881. http://www.flickr.com/photos/cpurrin1/2262636867/