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He declared that ontogeny the embryology and development of the individual briefly, and sometimes necessarily incompletely, recapitulated, or repeated, phylogeny the developmental history of the species or race. See biogenetic law. Early years Haeckel grew up in Merseburg , where his father was a government official. Such experiences in marine biology strongly attracted Haeckel toward zoology , but dutifully he took a medical degree, as his family wished, at Berlin in For a time he practiced medicine; his father then agreed to his traveling to Italy, where he painted and even considered art as a career.
At Messina he studied the one-celled protozoan group Radiolaria , members of which are strikingly crystalline in form; not surprisingly, Haeckel later maintained that the simplest organic life had originated spontaneously from inorganic matter by a sort of crystallization. Meanwhile, he completed a dissertation in zoology in at Jena and became privatdozent there. Darwin had described evolution through the natural selection of accumulated favourable variations that in time formed new species; to Haeckel, however, this was only a beginning, with consequences to be pursued further.
In he was appointed full professor, and he remained at Jena until his retirement in Get exclusive access to content from our First Edition with your subscription.
Haeckel, Ernst: Paleontological tree of vertebrates. Interestingly, though it was only on a theoretical basis, he suggested as early as that the cell nucleus was concerned with inheritance. His gastraea theory, tracing all multicellular animals to a hypothetical two-layered ancestor, stimulated both discussion and investigation. His propensities to systematization along evolutionary lines led to his valuable contributions to the knowledge of such invertebrates as medusae, radiolarians, siphonophores, and calcareous sponges.
Building collections around his own, Haeckel founded both the Phyletic Museum in Jena and the Ernst Haeckel Haus; the latter contains his books and archives, and it preserves many other mementos of his life and work.
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