George John Romanes (1848–94) was considered by The Times to be 'the biological investigator upon whom in England the mantle of Mr. Darwin has most conspicuously descended'. Incorporating some of Darwin's unpublished notes, this book explores the question of whether human intelligence evolved. In a stance still often considered controversial at the time of its first printing in 1888, the first half establishes a link between humans and animals, and introduces some of the most important issues of nineteenth-century evolutionary psychology: the impact of relative brain sizes of humans and primates, the origin of self-consciousness and the possible reasons behind the apparent mental stasis of what Romanes terms 'savage man'. Following the argument that one of the main factors to be considered is language, the second half focuses on philology. Romanes' earlier work, Mental Evolution in Animals (1883), is also reissued in this series.