Darwin from Descent of Man to Emotions under Domestication" which went on sale on 30 January 1868. He now published his ideas on human evolution and on how beautiful but apparently impractical features could have evolved in "The Descent of Man, and Selection in Relation to Sex". After revising "The Origin of Species" as the definitive 6th edition, his major works on species culminated in "The Expression of the Emotions in Man and Animals". This period was followed by extensive work on insectivorous plants and research into worms. Despite Darwin's concerns that his children were weakened as his wife Emma Darwin was his cousin or had inherited
The Expression of the Emotions in Man and Animals West Yorkshire. Darwin corresponded intensively with James Crichton-Browne, the son of the phrenologist William A. F. Browne and now the medical director of the Wakefield asylum. At the time, Crichton-Browne was preparing his extremely influential "West Riding Lunatic Asylum Medical Reports", and Darwin remarked to him that "The Expression" "should be called by Darwin "and" Browne". Darwin also drew on his personal experience of the symptoms of bereavement and studied the text of Henry Maudsley's 1870 Gulstonian lectures on "Body and Mind". He considered other approaches to the study of emotions, including their depiction in the arts – discussed by