Darwin from Descent of Man to Emotions bring Kew under his British Museum, Darwin commented that "I used to be ashamed of hating him so much, but now I will carefully cherish my hatred & contempt to the last days of my life". In October Hooker sent sun-dews and Venus fly-traps for Darwin's experiments, then was devastated when his bedridden mother died. In his hot-house Darwin experimented, giving such plants from around the world a variety of foods and poisons, and began writing "insectivorous Plants". "The Expression of the Emotions in Man and Animals" proved very popular, selling over 5,000 copies, but an exhausted Darwin became a
The Expression of the Emotions in Man and Animals with engravings of the Darwin family's domestic pets by the zoological illustrator T. W. Wood as well as work by the artists Briton Rivière, Joseph Wolf and A.D. May. It also included portraits by the Swedish photographer Oscar Rejlander (1813–1875), anatomical diagrams by Sir Charles Bell (1774–1842) and Friedrich Henle (1809–1885), as well as illustrational quotations from the "Mécanisme de la physionomie humaine" (1862) by the French neurologist Duchenne de Boulogne (1806–1875). As a result of his domestic psychology experiments, Darwin reduced the number of commonly observed emotions from Duchenne's calculation of more than sixty facial expressions, to just six