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 and a "geologizing expedition" – but actually spent some of his time re-exploring the old haunts of his undergraduate days. On the day of the coronation, 28 June 1838, Darwin was in Edinburgh. A few weeks later, he opened a private notebook with philosophical and psychological speculation – the "M Notebook" – and, over the next three months, filled it with his thoughts about possible interactions of hereditary factors with the mental and behavioural aspects of life.It should also be noted that Darwin made his first attempt at autobiography in August 1838. The critical importance of the "M Notebook" has