The Perpetuation of Living Beings, Hereditary Transmission and Variation / Lecture IV. (of VI.), "Lectures to Working Men", at the Museum of Practical Geology, 1863, on Darwin's Work: "Origin of Species"

The lecturer surveys contemporary knowledge of how organisms reproduce and vary, noting that origins of life remain obscure while mechanisms of perpetuation are well documented. He distinguishes asexual propagation—cuttings, bulbs, budding in polypes and infusoria, and parthenogenetic-like cycles in aphids—from sexual reproduction, in which egg and sperm or ovule and pollen combine to initiate development. He emphasizes that sexual union often re‑invigorates offspring, that progeny tend to resemble parents, and that sexual and asexual modes interact to shape heredity and variation, with practical examples and experimental demonstrations illustrating these principles.