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 Descent of Man, and Selection in Relation to Sex to the forces of sexual selection. While debates on the subject continues, in January 1871 Darwin started on another book, using left over material on emotional expressions, which became "The Expression of the Emotions in Man and Animals". In recent years controversy also involved the peacock tail, the most famous symbol of the principle of sexual selection. A seven-year Japanese study of free-ranging peafowl came to the conclusion that female peafowl do not select mates merely on the basis of their trains. Mariko Takahashi found no evidence that peahens expressed any preference for peacocks with more elaborate trains, such as