The Doctrine of Descent and Darwinism

according adaptation already Ammonites Amphibians animal world apes appearance Ascidian birds body bone brain causes Cetacea character characteristics comparative anatomy complete connection continent Darwin dentition derivation diverge doctrine of Descent Echinoderms embryo Eocene exhibit existence external facts families fauna fish formation fossil Gastrula gemmules genera genus geological Goethe grade gradually groups Haeckel heredity higher horse human hypothesis idea individual infer intermediate forms investigation islands lancelet language larva larvæ likewise linguistic lower mammals Marsupials Medusa ment merely metamorphosis modifications morphological mutability natural selection observations Oolite organisms origin ovum peculiar pedigree perfect period phase phenomena placenta plants polypes possess present primordial progenitors races regard relations remains reproduction reptiles Rütimeyer says scarcely scientific separate sexual Silurian skull species strata structure systematic terrestrial animals theory of selection tion transformation true Ungulata Ungulates varieties vertebral column Vertebrata vertebrate animals whole