Karl Ernst von Baer
Karl Ernst Ritter von Baer Edler von Huthorn (* 17th February July / 28th February 1792 greg. On Gut Piep (Estonian: Piibe ), today municipality Rakke , in Estonia Governorate , Russian Empire ; † 16 November July / 28th August . November 1876 greg. in Tartu , Governorate of Estonia) was a Baltic German physician and naturalist , especially zoologist , embryologist , anthropologist , geographer , explorer and discoverer of the human egg . He formulated the Baer rule of embryo similarity as well as the law named after him of the different erosion of river banks by the Coriolis force . He is considered one of the most important natural scientists of the 19th century and is sometimes referred to as the " Alexander von Humboldt of the North" because of his scientific achievements in numerous areas .
Its botanical-mycological author's abbreviation is " Baer ".
The son of the Estonian manor owner and district administrator Johann Magnus von Baer (1765-1825) and Julie Marie von Baer (1764-1820), daughter of a Russian officer, attended the German-speaking cathedral school in Reval , today's Tallinn , from 1808 to 1810 . He then studied medicine until 1814 at the then also German-speaking University of Dorpat , founded in 1802 , today Tartu. His most important teacher here was the anatomist and physiologist Friedrich Burdach , who came from Leipzig and who later brought him to Königsberg as a collaborator. After his doctorate (on endemic diseases of the Estonians: De morbis inter esthonos endemicis , 1814) , Baer continued his medical studies in Vienna and later in Würzburg , where Ignaz Döllinger became an important stimulus for him. In Vienna it became clear to Baer that he did not want to work as a doctor, but as a scientist, and in Berlin he completed his scientific training in 1816/17. In 1816 he accepted a position as a prosector at Burdach at the University of Königsberg , where he also received his habilitation . From 1817 to 1834 Baer lived in Königsberg; it was his most scientifically productive time. He was u. a. befriended the astronomer Friedrich Wilhelm Bessel and was in correspondence with important scientists, e. B. with the discoverer of the “gill systems” in humans, Martin Heinrich Rathke or with Alexander von Humboldt, to whom he later dedicated a worthy obituary.
In 1819 Baer married Auguste von Medem († 1864) from Königsberg; from this marriage had six children. In the same year Baer was appointed associate professor, two years later he took over the ordinariate of zoology from the Königsberg polymath Karl Gottfried Hagen , and in 1826 that of anatomy as well .
The achievements of Baers, who in the first years of his career mainly devoted himself to embryology, include
- the discovery of the human egg cell in 1827,
- the justification of comparative and human embryology based on the germ leaf concept,
- the first naming of the spermatozoa ,
- the knowledge of the chorda dorsalis as a fundamental, homologizable characteristic of all vertebrates and
- a systematic criticism of the recapitulation thesis .
In Königsberg , Baer began his research on embryology , which led him to the discovery of the egg cell , actually the egg, of mammals, especially humans, in 1827 . (From an egg can only after the formulation of the cell theory by Schleiden and Schwann 1838/39 be any question.) In order Baer has a centuries-long search for the "human egg" successfully. In the same year, he announced this, his most important discovery, in a letter written in Latin to the St. Petersburg Academy of Sciences ( De ovi mammalium et hominis genesi , Leipzig 1827) and in a German article in 1828 ( Commentar , in Heusinger's Zeitschrift fürorganischen Physik ) known. On September 23, 1828, Baer demonstrated suckling to the scientific audience at the gathering of German naturalists and doctors in Berlin. Baer first used the term “ spermatozoon ” (Greek for seed animals) in 1826. At that time, he considered the fertile function of these “living beings in sperm” to be (still) unproven.
In 1828 Baer was the first to describe the chorda dorsalis, which he called the back string (later vertebral or spinal string), as a common characteristic of vertebrates (or later so-called chordates): “ This string is not just the axis around which the first ones are Forming parts of the embryo, but also the true standard for the whole body and all main systems ”(so Baer 1828). This conceptual formation also meant the extension of the relationship of the human being up to the lampreys, an ingenious and therefore so fruitful idea.
Baer's embryological research is recorded in his two-volume monograph On the History of the Development of Animals (1828/1837), a book that the English obituary of 1876 acknowledged as the most important biological book of the 19th century. In this work, which includes mammals and birds as well as reptiles, amphibians, fish and invertebrates, Baer showed that the embryonic development in animals and humans progresses from more general to more and more specific characteristics ( Baer's rule ). While Christian Heinrich Pander had only demonstrated the cotyledons and their development on the chicken, Baer extended the model to the animal kingdom. In the embryonic development, vertebrate features appear first (such as the chorda dorsalis), then those of a bird, then those of a chicken, and finally those of a domestic chicken. This law of increasing differentiation stands in stark contrast to the idea of recapitulation as proposed by Lorenz Oken , Friedrich Meckel the Elder. J. and many others. There are no corresponding stages of development between different groups of animals, a vertebrate z. B. appears from the beginning (namely with the appearance of the chorda) as a vertebrate, but never as a "worm", mollusk or the like. Baer therefore (especially in the 5th Scholion of the History of Development , 1st vol.) Vehemently criticized this recapitulation hypothesis, which was later further developed by Ernst Haeckel into a basic biogenetic rule .
Academic career and honors
Baer went to the St. Petersburg Academy of Sciences in 1834 as the successor to his college friend, the embryologist Christian Heinrich Pander , where he worked as a zoologist from 1834 to 1846 and as an anatomist and physiologist from 1846 to 1862 . For a long time he was considered the “soul of the academy”. In 1862 he became an advisor to the Ministry of Education.
In 1820 he was admitted to the Leopoldina . In 1832 he was elected a corresponding member and in 1849 an external member of the Bavarian Academy of Sciences . In 1845 Baer was a founding member of the Russian Geographical Society , he was elected to the American Academy of Arts and Sciences in 1849 and to the Göttingen Academy of Sciences in 1851, and in 1859 he was the founding president of the Russian Entomological Society . He was a member of the St. Petersburg Academy of Sciences since 1826. He later became an honorary member of this academy. Since 1834 he was a corresponding member of the Prussian Academy of Sciences and a foreign member since 1861 , of the Académie des Sciences since 1858 and of the National Academy of Sciences since 1864 .
The baerente ( Aythya baeri ) was named after him.
Baer's research trips
In 1837 Baer collected animals and plants on Novaya Zemlya , a group of islands in the Arctic Ocean, where he also spent the summer. On further expeditions he explored traces of the Ice Age on the south coast of Finland (1838/1839). On the North Sea coasts , the Caspian Sea and in the Caucasus , he examined fisheries and fish stocks from 1851 to 1856. These investigations led to the first law protecting fish stocks in Russia in 1856 . With his research on the Arctic Ocean, Baer became one of the founders of scientific research in the Arctic.
Baer had observed that the valleys of the great Russian lowland streams show an asymmetry in which a right high bank - in the direction of flow - is accompanied by a left flat bank. He interpreted his observation through the influence of the Coriolis force on flowing water and formulated this thesis as a general law.
Works on anthropology and Darwinism
In Saint Petersburg, Baer turned to anthropology, geography, ecology and fisheries studies. In 1839, together with Gregor von Helmersen , he founded the first series of natural science books in Russia, the German-language contributions to the knowledge of the Russian Empire (Saint Petersburg 1839–1900, 45 volumes in total).
Before Darwin and on the suggestion of Pander, who in the 1820s had already considered an unlimited remodeling of species to be possible, Baer pondered evolution . In his essay On Papuas and Alfuren (1859) he spoke out against the constancy of species and in favor of a transformation of the species within a certain framework. He was opposed to the creation of new types through evolution, ultimately he saw the question of the origin of man as a problem that could probably never be solved. He presented his ideas in 1859, before the publication of Darwin's Origin of Species , on a trip to England a. a. Thomas Henry Huxley , with whom he was friends, and by whom he was compared to Darwin in 1882: “ Von Bär was another man of the same stamp as Darwin. "
In 1861, together with Rudolf Wagner, he organized the 1st anthropology congress in Göttingen, at which the measurement of human skulls was to be standardized. He dealt with historical and recent skulls and expanded the St. Petersburg craniological collection.
Baer commented publicly and critically on Darwinism first in the Russian journal Naturalist (1865-1867) and then in the Augsburger Allgemeine Zeitung (1873). In his 250-page essay On Darwin's Doctrine (1876), Baer criticized less Charles Darwin and the concept of evolution, as is often claimed, than the selection theory, which was intended to serve as an explanatory model, Huxley's concept of the ape kinship of humans and the far-reaching ideological conclusions drawn from evolutionary theory. He saw Darwinism as an innovative research hypothesis, a descent of humans from ape-like forms, the abandonment of teleologies in the explanation of nature and far-reaching "evolutionist" conclusions he rejected.
In 1876, Baer himself summed up his ambivalence and fascination with the theory of evolution as follows: “ First and foremost, I am unusually lucky that I am cited both as a supporter of Darwin's theory and as an opponent of it. In fact, I believe that I have provided some material for the justification of the same, even if Zeit and Darwin himself put a building on the foundation to which I feel alien. "
Baer promoted younger scientists and doctors, such as Nikolai Iwanowitsch Pirogow , Ilya Ilyich Metschnikow and Alexander O. Kowalewski . With the latter there was a dispute about the evolution of the sea squirts (ascidia), which Kowalewski viewed as relatives of the vertebrates, which Baer denied. Nevertheless, Baer Kowalewski and Metschnikow awarded the Baer Medal, donated in 1869, which was awarded for important achievements in the field of embryology.
From 1867 until his death in 1876, Baer lived in Dorpat , the city where he had once studied. Here he dealt with Darwinism and wrote numerous essays (some as long as a book) on biological, anthropological, scientific and cultural-historical topics (e.g. on ancient history, Homer or Ophir ).
Baer became a corresponding member of the Berlin Society for Anthropology, Ethnology and Prehistory, founded in 1869 . In 1867 he was awarded the important Copley Medal . The Baltic student union Estonia Dorpat awarded him the honorary philistine title . He was also accepted into the Prussian order Pour le Mérite for science and the arts on August 17, 1849 .
Baer died, blind, but worked scientifically until the end, in the late autumn of 1876 and was buried in the old Johannisfriedhof Dorpat (Raadi-Friedhof Tartu). In 1886 a memorial was erected to him on Toompea in Dorpat, which is still at the center of university events and student rites. The house where Baers lived and died in Tartu (Veski 4, ie Windmühlengasse) has been preserved and is now used as a museum and research facility. The volumes of the journal Folia Baeriana (Tartu), which appear at irregular intervals , have been continuously dealing with Baer's work since 1975.
Philosophical Positions: Between Teleology and Critique of Materialism
At the center of Baer's thinking is the concept of teleology : natural processes are characterized by purposefulness and purposefulness, embryonic development is a model for this. The main point of criticism of Darwinism is its non-recognition of a nature that can only be explained telelogically. At the same time, however, nature is constant change (of individuals, also of species, yes, of the entire cosmos), constancy is only appearance. Baer's thought experiment with changed forms of time and sequence of natural processes has a long history of effects that extends into philosophy and fiction well into the 20th century.
The denial of any “higher” purpose is also fed by Baer's criticism of materialism, another constant in his thinking. Embryonic development cannot be adequately explained causally and mechanically, but strives for a goal (sc. The developed organism) from the beginning. Mental phenomena or mental processes - called by Baer "longing for immortality" - cannot be explained materialistically. Here Baer was close to the anatomist Rudolf Müller , who was involved in the materialism dispute in 1854, but whose belief in revelation he rejected. For Baer, the modern natural sciences did not justify materialism; on the contrary, they led to the recognition of “idealistic” positions. At the same time, Baer also insists on the rejection of a “metaphysical” explanation of nature: the “primordial reason” of nature that he proclaims is not accessible to research.
Assessments, obituaries, criticism
- A new and great ally for you . Thomas Henry Huxley to Darwin, 1860.
- The greatest among the naturalists of our time, one of the greatest who ever lived . Georg Dragendorff (1836–1898), pharmacist, 1876.
- A founder of modern embryology, a naturalist of first order, an uncompromising opponent of Darwinism . Anonymous obituary in the Proceedings of the American Academy of Arts and Sciences , 1876.
- A universal scientific genius, greater than Carl von Linné or Georges Cuvier . Emil Rosenberg (1842–1925), anatomist and biologist.
- Baer's defense of the expediency of nature, his doctrine of the development of the organism from internal causes, his criticism of Darwinism, his recognition of the spirit in man and nature, his vitalistic thinking, his fight against materialism, his high regard and appreciation for Religion found energetic rejection or mockery at the time. That has changed today . Remigius Stölzle (1856–1921), philosopher and historian of philosophy, 1907.
- I would like to advise people who today, after having smelt a bit into Haeckel's, into Darwin's books, to do various other things before starting a branch for a monist association: for example, when Haeckel Ernst von Baer suggests picking up Karl Ernst von Baer himself and reading it. The earthly body, the earth, is the seedbed, and into it the spiritual germs are sunk so that they cover one another. This bear told the pure truth at the beginning of the 19th century! Rudolf Steiner (1861–1925), founder of anthroposophy, 1916.
- An evolutionist, (...) Of course, for him too, transmutation was a completely natural process, the existence of which cannot be doubted. (...) An inconsistent but practicing atheist who, as everyone knows, rejects the teachings of the Church . Boris Evgenjewitsch Raikow (1880–1966), Soviet historian of science, 1968.
- Yet von Baer had achieved more of the victory than modesty allowed him to state, for he had posited a general law of all biological development and, through it, thought he had glimpsed the essence of all development: the homogenous, coarsely structured, general, and potential develops into the heterochronous, finely built, special and determined. (...) This law of differentiation is the unifying theme of von Baer's entire work . Stephen Jay Gould (1941-2002), 1977
- The most brilliant opponent of Darwinian orthodoxy . Stephen Jay Gould, 1984.
- A scientist who expressly opposes the idea of evolution . Ernst Mayr (1904–2005), biologist
In the Federal Republic of Germany there has been a Karl Ernst von Baer Foundation since 1975 which supports scientific publications on the Baltic States. It was founded out of the Carl Schirren Society .
Karl Ernst von Baer is depicted on the front of the Estonian two-crown note.
- De ovi mammalium et hominis genesi , Leipzig 1827. doi: 10.5962 / bhl.title.68345 (here Baer announces his discovery of the human egg)
- On the history of the evolution of animals , 2 vols. Königsberg, 1828/1837. (the epoch-making work on comparative embryology) doi: 10.5962 / bhl.title.6303
- Investigations into the evolutionary history of fish . Leipzig 1835. doi: 10.5962 / bhl.title.5773
- Caspian studies . 4 parts. St. Petersburg 1855-1860. (Reprint: Saarbrücken 2006)
- About the extinction of animal species in physiological and not physiological respect in general . 1863 doi: 10.5962 / bhl.title.42322
- Studies in the field of natural sciences. Speeches held in scientific meetings and smaller essays of mixed content . 3 vols. Vieweg, St. Petersburg 1864–1876. (Reprint: Hildesheim, Zurich, New York 2003–2006) and Braunschweig 1886 ( digitized version ) doi: 10.5962 / bhl.title.1791
- News about the life and writings of the privy councilor Dr. Karl Ernst von Baer, communicated by himself , as a private print 1864, thereafter: St. Petersburg 1866 a. ö. (Reprint: Hannover-Döhren 1972) (Baer's autobiography until 1834, the year he moved to St. Petersburg)
- Which conception of living nature is the right one? Berlin, 1862.
- Development and Determination in Nature , ed. by K. Boegner. Stuttgart 1983. (Contains Baer's speeches on the teleology problem, with an anthroposophical list)
- Materials for the knowledge of the imperishable ground ice in Siberia. Unpublished typescript from 1843 and first permafrost knowledge , ed. by Lorenz King , Giessen 2001. ( digitized version )
- About a general law in the design of river beds . In: Caspian Studies 1860, VIII, pp. 1–6.
- About the climate of Sitcha and the Russian possessions on the north-west coast of America in general, together with an investigation into the question of which agricultural objects can flourish in these regions . Bull. Sci., 1839, 5, pp. 129-141, 146-152.
- Crania selecta ex thesauris anthropologicis Acad. Imp. Petropolitanae . Cum tabulis lithograficis XVI. / About Papuas and Alfuren In: Mémoires de l'Académie Impériale des Sciences de St.-Pétersbourg, VIme série, Vol. 19, Part 2, Vol. 8, 1859, pp. 241-268 and 269-346 (Latin work on craniology with German remarks on evolution also in humans)
- Does the larva of the simple ascidia develop after the vertebrate type? . In: Mémoires de l'Académie de St.-Pétersbourg VII. Série 1873, Vol. 8, pp. 1-35.
- To the argument about Darwinism . In: Augsburger Allgemeine Zeitung 1873, No. 130, supplement, pp. 1986–1988.
- Peter the Great's contribution to the expansion of geographical knowledge . St. Petersburg 1872.
- Cuvier’s life story . Braunschweig 1897.
- On the Genesis of the Ovum of Mammals and of Man . Introduction by Bernhard Cohen. In: Isis Vol. 47 (1956), pp. 117-153 (English translation of Baer's work on the discovery of eggs in 1827).
- The most general law of nature in all evolution . A presentation. In: Speeches and smaller essays, Vol. 1. St. Petersburg 1864 and 2006, pp. 35–74.
- On the relationship of the Prussian state to the history of human development . Presented on January 18, 1834 in the Royal German Society. In: Historical and literary treatises of the royal. Deutsche Gesellschaft zu Königsberg, 3rd Collection, Vol. 8, 1834, pp. 229–247.
- Look at the development of science . Lecture at the public meeting of the Academy of Sciences in St. Petersburg on December 29th. 1835. In: Speeches and smaller essays, Vol. 1. St. Petersburg 1864 and 2006, pp. 75–160.
- Which conception of living nature is the right one? and how does this concept apply to entomology? Talked about the opening of the Russian Entomological Society in May 1860. Separate print: Berlin 1862. (  ); also in: Speeches and smaller essays Vol. 1. St. Petersburg 1864 and 2006, pp. 237–284 (Here Baer unfolds his famous criticism of the renunciation of the concept of purpose and purposefulness in the natural sciences)
- An exchange of letters between Anders Adolf Retzius and Karl Ernst von Baer. Edited by Benno Ottow. (Bidrag till Kungl, Vetenskapakademiens Historia 3). Stockholm 1963.
- Perepiska Karla Bėra po problemam geografii. Publikacija perevod i primecanija TA Lukinoj. Leningrad 1970 (Russian)
- Письма Карла Бэра ученым Петербурга , ed. by TA Lukina. Leningrad 1976. (Baer letters mainly from the St. Petersburg period)
- Helmke Schierhorn: The correspondence between Karl Ernst von Baer (1792–1876) and Johann Christian Gustav Lucae (1814–1885) , in: Gegenbaurs morphologisches Jahrbuch Vol. 123 (1977) 3, pp. 353–386.
- Karl Ernst von Baer, Anton Dohrn : Correspondence , ed. by Christiane Groeben and Jane M. Oppenheimer. In: Transactions of the American Philosophical Society Vol. 83, Part 3 (1993).
- Thomas Schmuck: The correspondence between Alexander von Humboldt and Karl Ernst von Baer , in: HiN - Humboldt im Netz 24 (2012), pp. 5–20 (  ).
- Botany and passion. The correspondence between Christian Gottfried Daniel Nees von Esenbeck , Elisabeth Nees von Esenbeck and Karl Ernst von Baer. Edited by Ortrun Riha, Bastian Röther and Günther Höpfner. (Relationes Vol. 10). Aachen 2012.
- Ludwig Stieda : Karl Ernst von Baer. A biographical sketch . Braunschweig 1878 (first Baer biography, from the administrator of the Baer estate).
- Ludwig Stieda: Baer, Karl Ernst von . In: Allgemeine Deutsche Biographie (ADB). Volume 46, Duncker & Humblot, Leipzig 1902, pp. 207-212.
- Wilhelm Haacke: Karl Ernst von Baer . Leipzig 1905 (short biography).
- Goetz von Selle: New German Biography (NDB). Volume 1, Duncker & Humblot, Berlin 1953, ISBN 3-428-00182-6 , p. 524 ( ). In:
- Boris Evgenjewitsch Raikow : Karl Ernst von Baer (1792–1876). His life and his work . (= Acta historica Leopoldina; No. 5). JA Barth, Leipzig 1968. (Marxist-Orthodox biography of Baer).
- T. Ilomets: Karl Ernst von Baer . Tallinn 1976 (Estonian, Russian, German) (illustrated book about Baer's life)
- Karl Ernst von Baer, the Humboldt of the north . Exhibition catalog. University of Giessen, Giessen 2002
Obituaries and memorials about Baer
- Leopold von Schrenck : Speech given at the grave by academic Dr. v. Schrenck. In: Speeches in memory of CE von Baer's, given at the funeral ceremony in Dorpat. Dorpat 1876.
- Ray Lankester : Karl Ernst von Baer . In: The Academy Vol. 10, 1876, pp. 608-609.
- Alexander Graf Keyserling : memorial speech for Karl Ernst von Baer, given on Dec. 18, 1876 in the literary society of Reval . In: From the Baltic spirit world. Speeches and essays. Vol. 1, Riga 1908, pp. 3-17.
- Gustav Zaddach: Karl Ernst von Baer . Commemorative speech given at the extraordinary meeting of the physical-economic society on February 16, 1877. Königsberg 1877.
- Gregor von Helmersen : Karl Ernst von Baer's last hours of life . In: St. Petersburg Newspaper No. 151, 1877, pp. 1-8.
- Karl Johann von Seidlitz: Memorial lecture for Karl Ernst von Baer, November 25, 1876 . In: Meeting reports of the natural scientist society in Dorpat, Vol. 4, 1878, pp. 285–305.
Georg Dragendorff : memorial address on Baer. In: Meeting reports of the natural scientist society in Dorpat (or at the University of Jurjew), Vol. 4, 1878, pp. 282–285.
- dsb .: Baers life outline. Ibid. Vol. 10, 1895, pp. 27-40.
- Emil Rosenberg: Ceremonial speech on the day of the unveiling of the monument to Karl Ernst von Baer in Dorpat held in the university auditorium on November 16 (28) 1886 . Dorpat 1886.
- Georg Seidlitz: Baer and the Darwinian theory . In: Contributions to the Descendence Theory. Leipzig 1876, pp. 37–170.
- Филипп В. Овсянников: Очерк деятельности К.М. Бэра и значение его трудов . St. Petersburg 1879 (Russian).
- Remigius Stölzle: Karl Ernst von Baer and his worldview . Regensburg 1897 (synthesis of Baer's world view with theistic list).
- Benno Ottow (Hrsg.): Karl Ernst von Baer: About the formation of the egg of mammals and humans . Leipzig 1927.
- George Sarton: The discovery of the mammalian egg and the foundation of modern embryology . In: Isis Vol. 16 (1931), No. 2, pp. 315–377 (with a facsimile of Baer's original work from 1827).
- Theodor Arzt: The history of research on the chorda dorsalis and the origin of the term chordata in the 19th century . In: Nova Acta Leopoldina NF (1955) No. 121, pp. 361-409.
- Benno Ottow: KE von Baer as a craniologist and the anthropologist meeting in Göttingen in 1861 . In: Sudhoffs Archiv Vol. 50 (1966), pp. 43-68.
- Heinrich von Knorre: The history of the origins of KE Baer's "Mission Statement": De ovi mammalium et hominis genesi 1827 and four letters from Karl Ernst von Baers to Carl Asmund Rudolphi . In: Mitteilungen der Deutschen Akademie der Naturforscher Leopoldina, Series 3, Vol. 17 (1973), pp. 237–286.
- Heinrich von Knorre, Helmke Schierhorn: Karl Ernst von Baer (1792–1876). An iconographic study . In: Acta historica Leopoldina No. 9 (1975), pp. 227-268 (collects all Baer portraits).
- Ospovat, Dov (1976). The influence of Karl Ernst von Baer's embryology, 1828–1859 . In: Journal of the History of Biology Vol. 9 (1976) No. 1, pp. 1-28.
- Maie Valt: KE v. Baer yes darvinism. Etüüd arenguideede draamast bioloogias . Tallinn 1977. (Estonian)
- Hans Querner: Karl Ernst von Baer as an anthropologist . In: Peter Schröter (ed.): 75 years of anthropological collections in Munich. Munich 1977, pp. 301-310.
- Roswitha Lienert: Karl Ernst von Baer and the discovery of the mammalian egg . Med. Diss. Würzburg 1978
- Hans Querner: Karl Ernst von Baer and Thomas Henry Huxley. Unpublished letters from 1860–1868 . In: Sudhoffs Archiv Vol. 62 (1978) No. 1, pp. 131-147.
- Erki Tammiksaar: Finding aid for the estate of Karl Ernst von Baer (1792–1876) . (= Reports and works from the university library and the university archive Giessen; 50/1999). Giessen University Library, Giessen 1999 ( digitized introduction ).
- Erki Tammiksaar: The "Humboldt of the North". The estate of the natural scientist Karl Ernst von Baer in the university library is being evaluated . In: Mirror of Research . Volume 17, 2000, Issue 2, pp. 14-21 ( digitized version ).
- Erki Tammiksaar, Sabine Brauckmann: Karl Ernst von Baer's "On the History of the Development of Animals II" and its unpublished drawings. In: History and Philosophy of the Life Sciences 26 (2004) 3-4, pp. 291-308.
- Carola L. Gottzmann , Petra Hörner: Lexicon of the German-language literature of the Baltic States and St. Petersburg . De Gruyter, Berlin 2007, ISBN 978-3-11-019338-1 , p. 161-157 .
- Thomas Schmuck: Baltic Genesis. The foundation of embryology in the 19th century . (= Relationes Vol. 2). Aachen 2009 (on Baer: pp. 115–213).
- Erki Tammiksaar: New Aspects in Karl Ernst von Baer's World View Concerning Darwin's Hypothesis of Natural Selection . In: Э. И. Кольчинский, А. А. Федотова: Чарльз Дарвин и современная биология. Труды Международной научной конференции, Санкт-Петербург, 21–23 сентября 2009 г. St. Petersburg 2010, pp. 561-566.
- Ortrun Riha , Thomas Schmuck: "The most general law". Karl Ernst von Baer (1792–1876) and the great discourses of the 19th century . (= Relationes Vol. 5). Aachen 2011.
- Sabine Brauckmann: Karl Ernst von Baer (1792–1876) and evolution. In: International Journal of Developmental Biology Vol. 56 (2012), pp. 653-660.
- Literature by and about Karl Ernst von Baer in the catalog of the German National Library
- Literature by and about Karl Ernst von Baer in the catalog of the Virtual Library of Biology (vifabio)
- Author entry and list of the described plant names for Karl Ernst von Baer at the IPNI
- Baltic Historical Commission (ed.): Entry on Karl Ernst von Baer. In: BBLD - Baltic Biographical Lexicon digital
- Short biography (English) in the Virtual Laboratory of the Max Planck Institute for the History of Science
- Digital sources in full text in the Virtual Laboratory of the Max Planck Institute for the History of Science
- Album academicum of the Imperial University of Dorpat , Dorpat 1889
- Good Piep (Estonian)
- Finding aid for the estate (PDF; 7.7 MB)
- Virtual exhibition of the Tartu University Library on the life and writings of Baer
- Notice , on Rambow Genealogy
- Date after his autobiography News about the life and writings of the privy councilor Dr. Karl Ernst von Baer , Saint Petersburg 1865.
- Genealogical Handbook of the Baltic Knights , Görlitz 1930, pages 12 , 13 including FN 6 , 14.
- In memory of Alexander von Humboldt . Address to the mathematical-physical class on May 13, 1859. Separate print. Reprinted in: Speeches and smaller essays Vol. 1. St. Petersburg 1864 and 2006, pp. 293–296 The exchange of letters: http://www.uni-potsdam.de/u/romanistik/humboldt/hin/hin24/ jewelry.htm
- Roswitha Lienert: Karl Ernst von Baer and the discovery of the mammalian egg. Medical dissertation in Würzburg 1977.
- Alexander von Humboldt , Martin Hinrich Lichtenstein : Official report on the assembly of German natural scientists and doctors in Berlin in September 1828. Berlin 1829, p. 26. In his autobiography, written much later, Baer complained about the comparatively low response to his important discovery.
- quoted in Karl Friedrich Burdach : Physiology as empirical science . Vol. 1, Leipzig 1826, p. 90, (cf. Th. Schmuck: Baltische Genesis. The foundations of modern embryology . Aachen 2009, p. 182).
- Doctor: The history of research into the chorda dorsalis ... p. 367
- "The most important biological work of the century" (anonymous obituary in the Proceedings of the American Academy of Arts and Sciences 1876/1877, p. 335).
- Schrenck, Obituary for Baer ... 1876, pp. 27–28.
- Member by Karl Ernst von Baer (with picture) at the German Academy of Natural Scientists Leopoldina , accessed on February 7, 2016.
- Member by Karl Ernst von Baer (with picture) at the Bavarian Academy of Sciences , accessed on February 6, 2016.
- Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 30.
- Foreign members of the Russian Academy of Sciences since 1724. Karl Maximowitsch (Karl Ernst) von Baer. Russian Academy of Sciences, accessed August 7, 2015 (Russian).
- Members of the previous academies. Karl Ernst von Baer. Berlin-Brandenburg Academy of Sciences , accessed on February 17, 2015 .
- Herbert Wilhelmy : Geomorphology in key words. II. Exogenous morphodynamics. Verlag Ferdinand Hirt Kiel, pp. 97/98.
- Quoted from Jane M. Oppenheimer: An Embryological Enigma . In: B. Glass, O. Temkin, WL Straus Jr. (Eds.): Forerunners of Darwin 1745-1859. Baltimore MD 1968, p. 294
- On Darwin's teaching. In: Speeches and smaller essays, Vol. 2. St. Petersburg 1876, p. 239
- Studentenkurier 01/2002, p. 3.
- Source: The Orden pour le merite for science and the arts: The members of the Order , Volume I (1842–1881), page 134, Gebr. Mann-Verlag, Berlin, 1975
- http://baer.emu.ee/253571 ( Memento from February 9, 2007 in the Internet Archive )
- See Hans Blumenberg: Lifetime and World Time. Frankfurt / M. 1986
- Cf. Which conception of living nature is the right one? ... from 1860, in: Reden Vol. 1, p. 269
- Letter from Huxley dated August 6, 1860, after JM Oppenheimer: An Embryological Enigma. In: B. Glass, O. Temkin, WL Straus Jr. (Eds.): Forerunners of Darwin 1745-1859. Baltimore MD 1968, p. 295
- lecture http://fvn-rs.net/PDF/GA/GA174b.pdf
- BE Raikow, Karl Ernst von Baer 1792–1876. (= Acta historica Leopoldina vol. 5). Leipzig 1968, pp. 403 and 418
- St. J. Gould: Ontogeny and Phylogeny. Cambridge 1977, p. 61
- St. J. Gould: Darwin after Darwin. Frankfurt / M., Berlin, Vienna 1984, p. 136.
- E. Mayr The development of the biological world of thought. Berlin, Heidelberg, New York, Tokyo 1984, p. 207
|SURNAME||Baer, Karl Ernst von|
|BRIEF DESCRIPTION||German-Baltic naturalist|
|DATE OF BIRTH||February 28, 1792|
|PLACE OF BIRTH||Estonia|
|DATE OF DEATH||November 28, 1876|
|Place of death||Dorpat|