The Darwinian Theory of the Transmutation of Species

able according acknowledged action advance advantage ages animals appear arrangement beauty become bees beginning believe birds blood body bones called cause certain character common condition considered continually course created creation creatures Darwin developed difficulty direction distinct earth effected evidence existence explain expressed fact favoured female fishes formation forms geology give habits hand heart horse human imagination improvement individual instance instinct learned less light living lower matter means millions modification Natural Selection never object observed organic origin passage perfect period plants present principle produced progenitor progress proof proved question race reason remarks result says seems seen Silurian soil species sterility structure struggle succession suppose term Theory things thousand tion transformation Transmutation true turn varieties vertebrated whole