The Expression of the Emotions in Man and Animals by Charles Darwin was published in 1872. Darwin's book is among the most enduring contributions from 19th century psychology. It deals almost entirely with emotional display, but assumes a great deal about the nature of what is being displayed. Although premised on an unsupportable interpretation of the nature of "expression," it is this idea that permeates the majority of work on emotional experience within psychology. The Expression of the Emotions is an important landmark in the history of book illustration. Captioned: Figure 18, Chimpanzee disappointed and sulky, drawn by Thomas William Wood.