The Expression of the Emotions in Man and Animals typically accompanies blushing. A German translation of "The Expression" appeared in 1872; Dutch and French versions followed in 1873 and 1874. A second edition of the book, with only minor alterations, was published in 1890. Before Darwin, human emotional life had posed problems to the western philosophical categories of "mind" and "body". Darwin's interest can be traced to his time as a medical student and the 1824 reprint of Sir Charles Bell's "Anatomy and Philosophy of Expression" which argued for a spiritual dimension to the subject. In contrast, Darwin's biological approach links mental states to the coordination of movement, and
The Formation of Vegetable Mould through the Action of Worms went the less controversial direction of the lowly worm. His network of correspondents and fans responded to his interest and "earthworm anecdotes began surfacing in his mountain of mail". He had been interested in earthworms "since his first fishing days at The Mount and flirting days at Maer". Still, other work constrained him. Broken off from "Descent", he had to finish his next work "The Expression of the Emotions in Man and Animals". By 1876, with his first grandson on the way, he felt his writing life was nearly over, with so much unfinished. He wanted to write on earthworms