Baer Karl Ernst von

(b. Piep, near Jerwen, Estonia, 28 February 1792; d. Dorpat, Estonia [now Tartu, Estonian S.S.R.], 28 November 1876), biology anthropology, geography

During the earlier years of his professional life, Baer concentrated his principal efforts on what is now known as embryology. He is known to Western biologists for his discovery of the mammalian egg in 1826 and for his treatise Ueber die Entwickelungsgeschichte der Thiere, Beobachtung und Reflexion (1828, 1837), the publication of which provided a basis for the systematic study of animal development. Baer was a professor in Germany when he carried out his embryological investigations. When he was about forty-two years old, he left Germany for Russia; there, during the remaining years of his long, active life, he devoted his attention primarily to anthropology, both physical and ethnographic, to geography, and, to lesser degree, to archaeology. But this gives only a bare indication of how widely and how philosophically his mind ranged through nature.

Baer whose complete style was Karl Ernst Ritter von Baer, Edler von Huthorn, was descended from an originally Prussian family. One of his ancestors Andreas Baer, emigrated from Westphalia to Reval Livonia in the mid-sixteenth century; a collateral descendant of Andreas bought an estate in Estonia during the mid-seventeenth century and was made a member of the nobility. Karl’s father, Magnus Johann von Baer, was an Estonian landholder whose estate, Piep, was modest in size He had been trained in law and, after Karl’s birth, served a term as a district official (Landrat) and as an official of the Estonian knighthood, in which the family had gained membership during the late eighteenth century.

Magnus Johann von Baer married his first cousin Juliane Louise von Baer. Karl was one of ten children, of whom three were sons. His parents, because of the large size of the family, entrusted Karl during his early years to his father’s brother Karl and his wife. Baroness Ernestine von Canne, from Coburg, who lived on a neighboring estate and were childless. Here Karl acquired the love of plants that later drew his interest to botany and natural history. He returned to his own family when he was seven. His first formal instruction was from tutors at home; then, from 1807 to 1810, he attended a cathedral school for members of the nobility in Reval

Baer’s uncle Karl had enjoyed a military life and hoped that his nephew would follow a similar career, as did the boy’s father. When Karl decided to enter a university instead, his father encouraged him to go to Germany, but he insisted on entering the University of Dorpat, opened six years earlier. He matriculated in August 1810 as a medical student, perhaps to prepare himself for a career in natural science. He later said that he did not know why he decided to take a medical degree.

Dorpat was a small university, and a provincial one. Baer was interested, however, in his work in botany, physics, and physiology. The professor of physiology was Karl Friedrich Burdach, who later exerted further influence on Baer’s career. Baer received the M.D. at Dorpat in September 1814. He was dissatisfied with his medical training, however, and continued his studies in Berlin and Vienna in 1814–1815 and in Berlin during the winter semester 1816–1817.

Baer went to Würzburg in 1815 further his medical studies, but as an indirect of his interest in botany he met Ignaz Döllinger, one of the great teachers of the nineteenth century. During the academic year 1815–1816 he studied comparative anatomy with Döllinger, an experience that was critical for his later career. At that time Döllinger tried to persuade him to study the development of the chick by improved methods, studying the blastoderm removed from the yolk, but Baer was not willing to spend the time or money that would have been necessary. He was instrumental, however, in bringing to Würzburg Christian Heinrich Pander, whom he had known in Dorpat and Berlin, and Pander began the study.

In August 1817, Baer went to Königsberg as prosector in anatomy at the invitation of Burdach, who was professor there. In 1819 he became extraordinary professor of anatomy, and in 1826 ordinary professor of zoology. At various times during his years at Königsberg he taught zoology, anatomy and anthropology. Baer founded a zoological museum, acted several times as director of the botanical gardens, and served terms as dean of the medical faculty and as rector of the university. He married Auguste von Medem of Königsberg on 1 January 1820. They had five sons and a daughter; the first son died in childhood; the second, Karl, who was interested in natural history died of typhus at the age of twenty-one while a student at the university of Dorpat.

Most of Baer’s contributions to embryology were made between 1819 and 1834, when he was in Königsberg. He made a number of specific discoveries in vertebrate morphogenesis relating to the development of particular organs or organ systems. These alone would have sufficed to warrant his inclusion among major contributors to embryology. He was the first to discover and describe the notochord. He was among the first to recognize that the neural folds represent the rudiment of the central nervous system and that they from a tube, although he did not understand the precise mechanism by which the folds form the substance of brain and spinal cord. He was the first to describe and name the five primary brain vesicles. He made considerable advances in the understanding of the development and function of the extraembryonic membrances (chorion, amnion, allantois) in the chick and the mammal. Incidentally, he was responsible for the introduction of the term “spermatozoa” for what were then known as animalcules in the seminal fluid (but he thought them parasites).

Baer’s greatest contributions to embryology were of far wider general significance. In 1826 he discovered the egg of the mammal in the ovary, bringing to completion a search begun at least as early as the seventeenth century. William Harvey had unsuccessfully attempted to find eggs of the deer in the uterus; others after Harvey;s time, had mistaken ovarian follicles for mammalian eggs. Baer first found the true egg in Burdach’s house dog, a bitch sacrificed for the investigation; subsequently he found eggs in a number of ther mammals. Thus he concluded that “every animal which springs from the coition of male and female is developed from an ovum, and none from a simple formative liquid” (De ovi mammalium ethominis genesi, O’Malley trans., p. 149). This was a unifying doctrine whose importance cannot be over emphasized

Equally important were Baer’s careful descriptions and thoughtful interpretations of the whole course of vertebrate development. He had been in Würzburg in 1815–1816 when his friend Pander had first analyzed the development of the chick in terms of germ layers, and he had participated in that work . In Köonigsberg, Baer continued the work begun by Pander, extending the observations and generalizing their meaning. Some of his ideas were first published in contributions to Volumes I and II (1826, 1827) of Burdach’s Die Physiologie als Erfahrungswissenschaft. The first volume of Baer’s own treatise was published in 1828, the second volume (unfinished) in 1837; part of what was lacking in Volume II was published posthumosly in 1888. Entwickelungsgeschichte was the key word in his title and his thought; his great contribution rested on his ability to envisage the organism as a historical entity, as a being that undergoes observable change during its life. He described the development of vertebrates from conception to hatching or birth. Bear observed the formation of the germ layers and described the way in which they formed various organs by tubulation, and he knew this to be more or less similar in all vertebrates. Even more important, he emphasized that development is epigenetic, that it proceeds from the apparently homogeneous to the strikingly heterogeneous, from the general to the special. The old idea, long disputed, that embryonic parts might be preformed in the egg was no longer tenable after Baer’s work.

In discussing he view that development proceeds from the general to the special, Baer emphasized that embryos resemble each other more than adults do, and he strongly opposed the opinion previously expressed by Johann Friedrich Meckel that embryos resemble adults of other species. As part of the heritage of German Naturphilosophie in which he had been trained, Baer had a great interest in symmetry. His embryological observations led him to believe that there are four fundamental animal types that differ from each other according to their symmetry: the peripheral or radial, the segmental, the massive and the double symmetrical (vertebrate). These types were very similar to the four embranchements described at approximately the same time by Cuvier. Baer held some belief in limited transformationism, the idea that one kind of animal species might during the course of history be transformed into another, but when Darwin’s Origin of Species was published (1859) Baer could not agree that all organisms could have evolved from a single or a few progenitors. Unfortunately, Baer’s valid objections to Meckel’s inter pretations where ignored by Darwin’ immediate followers, who mad the recapitulation doctrine a key to evolution theory. But when the new analytical and experimental approach to the study of development began to be followed in the late nineteenth century, the new pathways led out not form the ideas of the recapitulationists, but from those of Baer.

Although Baer reached the peak of his career as an embryologist when at Königsberg, he was restless, and for reasons not yet fully understood, he was unwilling to remain there. He was elected a corresponding member of the Academy of Sciences in St., Petersburg in 1826, and in 1828 he refused an invitation to work at the academy, even though his friend Pander was already there as academician. Baer spent several months in St. Petersburg in 1829–1830, but found conditions for work less favorable than in Königsberg Nonetheless, when his elder brother Louis, who had been managing the estate at Piep, died in 1834, Baer moved with his wife and children to St. Petersburg. His wish to retain the Piep estate for his family and broken health resulting from overwork may have been factors contributing to a move that had not seemed desirable earlier. Baer entered the academy as a full member in zoology in December 1834, and remained there for the rest of his working life. He performed many duties, his first appointment being as librarian for the foreigns division. In 1846 Baer became academician for comparative anatomy and physiology, and from 1846 to 1852 he served as ordinary professor in those fields at the Medico-Chirurgical Academy in St. Petersburg. He retired from active membership in the Academy of Sciences in 1862 but continued work as an honorary member until 1867. He then returned to Dorpat, where he resided until his death.

When he became academician for comparative anatomy and physiology, Baer took charge of the academy’s anatomical museum, a decision related to his long-standing interest in anthropology. His doctoral dissertation (1814), on diseases endemic among Estonians, was ethnographically inclined. He first lectured on anthropology as early as the winter of his first year in Königsberg (1817–1818), to students of all faculties, not only of medicine. One volume of these lectures was published in 1824; a second, although promised, did not appear.

In the 1820’s while he was still in Königsberg, Baer had contemplated a trip to Lapland and Novaya Zemlya. After becoming an academician in St. Petersburg, he was able to satisfy his desire for travel. In 1837 he headed an expedition to Novaya Zemlya under the auspices of the academy and was the first naturalist to collect specimens there. During more than twenty-five years he made a number of scientific expeditions, traveling widely; to Lapland, to the North Cape, to the Caspian Sea and the Caucasus, to the Sea of Azov, to Kazan, and to other far parts of Russia, as well as on the Continent and in England. Baer made a number of important discoveries in natural history and geology, and contributed beginning in 1845, to the founding of the Russian Geographical Society. From 1839 he was coeditor of and contributor to be important Beiträge zur Kenntniss des Russischen Reiches and der argräanzender Länder Asiens. His travels also increased his already considerable interest in ethnography.

Baer classified man into six categories ranked according to the degree of primitiveness. His interpretations of some peoples as more primitive than others were similar to those of his contemporaries and immediate predecessors; he did not bring to this area of investigation the same vision that he had carried into embryology. Nonetheless, at least one of his contributions to modern anthropology was truly effective. After he became academician for comparative anatomy and physiology, one of his primary accomplishment, perhaps growing out his earlier museum experience in Königsberg, was the establishment at the academy of a craniological collection. Attempts to classify skulls were based on measurements, and Baer thought it desirable that methods of cranial measurement be standardized. To this end, he called together a group of craniologists in Göttingen in 1861. The measurements were not standardized, but the meeting led to the founding of the German Anthopological Society and of the German Archiv für Antrhropologie.

Baer’s scientific and intellectual interests reached beyond the areas already enumerated. He did some work in entomology and was instrumental in the establishment of the Russian Entomological Society, of which he was the first president in 1860. He was deeply interested in pisciculture and in the Russian fisheries . He wrote on the origin of the tin found in ancient bronze on the routes of Odysseus’ voyages and on the whereabouts of biblical Ophir.

Among his other abilities Baer had particular talents that distinguished him socially. He had great wit, which endeared him to those who knew him, and he was very loyal to his friends. One friend in particular may he signed out. In the winter of 1839–1840 Baer made the acquaintance of the Grand Duchess Helen Pavlovna, the former Princess Frederika Charlotte Marie of Württemberg. The wife of Grand Duke Michael Pavlovitch youngest brother of Czar Alexander I, she was an enlightened and intelligent patron of the arts and the sciences; Baer instructed her two daughters in natural history and enjoyed her friendship for many years.

Baer was patriotic Russian, as is clear from the zeal with which he carried out his duties for the academy and from his evident interest in Russian geography and ethnography. But he was also an expressed enthusiast of Prussia. His true political views remain obscure, for some were expressed cryptically and others, we are told by his biographer Stieda, were probably eliminated from his publications by the censors.

As for his writing, Baer began more than he completed. The second volume of his great Entwickelungsgeschichte was never finished; he neglected even to read the proofs when the publisher decided to bring it out unfinished. He began, but failed to complete, other writings; he never completely described his collections from Novaya Zemlya. Nonetheless, he was a prolific lecturer and author. The second edition of Stieda’s biography enumerates approximately 300 of his publications, and the list is incomplete.

Baer was not only an accomplisher but also a thinker, and the range and profundity of his thought are reflected in many of his writings. He was particularly interested in problems related to teleology; he lectured and wrote on living creatures and life as related to the wider cosmos. Baer saw nature as a whole, not merely as did the Naturphilosophen, who constructed elaborate ideas about natural schemes but as an observer and discoverer who with his eyes as well as his mind searched deep into many of nature’s realms.

Baer received many honors during his lifetime. An island in the Russian North was named for him; and in 1864 the Estonian Knights held a celebration for him on the golden jubilee of his doctorate. They also published his autobiography, which was especially prepared for that event. In 1872, Volume 5 of the Archiv für Anthropologie was dedicated to him. Baer was elected a member of the Royal Society of London and of the Paris Academy. He was awarded the Copley Medal by the Royal Society and also received a medal from the Paris Academy. Alexander von Humboldt personally brought him the medal from Paris much to Baer’s delight. Baer once wrote of Humboldt that he was “versatile, yet always accurate as an observer, deep and far-seeing as a thinker, exalted as a seer” (Reden I 296). He might well have been speaking of himself.

BIBLIOGRAPHY

The most important sources of information about Baer’s life and writings are his autobiography and an authoritative biography by Ludwig Stieda. Both contain extensive classified and annotated lists of publications by Baer.

I. Original Works. Baer’s writings include De ovi mammalium et hominis genesi epistola (Leipzig 1827) German trans; B. ottow ed., Ueber die Bilding des Eies der Säugetiere und des Menschen (Leipzig, 1927); fascimile of Lating ed., in George Sarton “The Discovery of the Mammalian Egg and the Foundation of Modern Embryology” in Isis16 (1931)315–[378]; English trans. by Charles Donald O’Malley ibid., 47 (1956), 117–153; Ueber die Entwickelungsgeschichted der Thiere. Beobachtung und Reflexion, 2 vols. (Königsberg, 1828, 1837), Vol. III L. Stieda, ed. (Königsberg 1888); Reden gehalten in wissenschaftlichen Versammlungen und kleinere Aufsätze vermischten Inhalts, 3 Vols (St. Petersburg, 1864–1876); and Nachrichten über Leben und Schriften des Geheimrathes Dr. Karl Ernst von Baer, mitgetheilt von ihm selbst. Veröoffenlicht bei Gelegenheit seines fünfzigiährigen Doctor-Jubiläums, am 29. August 1864, von der Ritterschaft Ehstlands (St. Petersburg, 1865), privately distributed ed. of 400 copies; trade eds. appeared under same title (St. Petersburg, 1866; 2nd ed., Brunswick, 1886).

II Secondary Literature Works on Baer include B. Ottow “K.E. von Baer als Kraniologe und die Anthropologen-Versammlung 1861 in Göttingen,” in Sudhoffs Archiv für Geschichte der Medizin und der Naturwissenschaften, 50 (1966), 43–68; and L. Stieda, Karl Ernst von Baer. Eine biographische Skizze (Brunswick, 1878, 1886).

Jane Oppenheimer