The Living Thoughts of Darwin

adaptation allied animals and plants ants appears beak become modified believe biological biologists birds breeding-season breeds Chap CHARLES ROBERT DARWIN classification closely coloured complex continued Darwin degree display distinct species domestic doubt early effect embryos evolutionary extinct feathers females formation forms fossils genera genes genus geological groups habits Hence horse important individual differences inhabitants inherited insects instance instincts intermediate Josiah Wedgwood JULIAN HUXLEY kinds labellum larvæ legs living lower animals males mammæ mammals manner marsupials mutation natural selection naturalists nest neuters occur ocelli offspring organisation Origin Origin of Species period pollinia possess principle produced progenitors pupa quadrupeds relation remarkable resemblance rock-pigeon rudimentary organs sanguinea secondary sexual characters seeds seen sexes sexual selection shoulder-stripe similar slave-making slaves slight sometimes South America SPINOZA striped structure struggle for existence tail theory tion variability variation varieties various Welsh ponies whole wings worms