The Law of Heredity: A Study of the Cause of Variation, and the Origin of Living Organisms

acquired action adult alike allied species ancestor ancestral form asexual asexual reproduction become birds body breed characteristics color common conclusion confined crossing crustacea Daphnia Darwin Darwin says descendants domesticated animals domesticated pigeons embryo epigenesis evolution existence experience explanation fact female fertilized fortuitous fowls functions furnishes gemmules genera genus germ germinative vesicle give rise gradually greatly hereditary homology horns hybrid hydroids hypothesis individual influence inherited insects latent male cell male element males of allied medusa ment modification natural selection offspring ordinary origin origin of species ovum pangenesis parent parthenogenesis peculiarities perfect phenomena plants plastidules plumage present produced pure race reasons for believing reciprocal crosses reproductive elements resemblance result secondary sexual characters sexes sexual elements sexual reproduction sexual selection similar simply striped structure tendency to vary theory of heredity throw off gemmules tion transmission transmit true variable various young