The publication of Origin of Species in 1859 transformed Darwin from a respected scientist into a controversial public celebrity. In the last twenty-four years of his life, in spite of frequent bouts of illness, Darwin published widely on both evolution and his other scientific interests.
His second great evolutionary work, Variation of Plants and Animals Under Domestication (1868) left out his thoughts human evolution, which were later published in The Descent of Man, and Selection in Relation to Sex (1871). The Expression of the Emotions in Man and Animals (1872), one of the first books to feature printed photographs, developed his theories on evolutionary psychology.
Other works treated the movement of climbing plants (1875), insectivorous plants (1875), cross and self-fertilisation of plants (1876), flowers (1877), and phototropism (1880). In his final book (1881), he returned to the effect of earthworms on soil formation, a topic which had fascinated him throughout his life.