On Germinal Selection as a Source of Definite Variation

A Mechanico-Physiological Theory of Organic Evolution

Darwin, and After Darwin, Volumes 1 and 3 An Exposition of the Darwinian Theory and a Discussion of Post-Darwinian Questions

A Critical Examination of the Position of Mr. Darwin's Work, "On the Origin of Species," in Relation to the Complete Theory of the Causes of the Phenomena of Organic Nature Lecture VI. (of VI.), "Lectures to Working Men", at the Museum of Practical Geolo