Baer, Karl Ernst

BAER, KARL ERNST. - Estonian naturalist, b. at Piep in 1792, d. at Dorpat (Tartu) in 1876. Having taken his degree in medicine at Dorpat, he went in 1815 to Würzburg to study anatomy at the school of Döllinger. In 1827 he was appointed professor of zoology at Königsberg and from 1829 he taught zoology, anatomy and physiology at St. Petersburg for more than thirty years.

Baer's greatest fame derives from his studies in embryology (v.). Into this science he introduced the method of direct observation and comparison, adding the embryological criterion to the comparative-anatomical one in the study of the systematics and classification of animals (v.). He enunciated the fundamental laws of development, elaborating the concept of progressive differentiation and upholding the epigenetic theory. In 1827 he discovered the mammalian egg and described it in the Epistola de ovis mammalium et hominis genesi. He also studied the embryology of numerous invertebrates and gave the name paedogenesis to the phenomena of larval parthenogenesis. His principal work on embryology is Untersuchungen über die Entwicklungsgeschichte der Thiere, Beobachtung und Reflexion (I, Königsberg 1827; II, ibid. 1837); to it must be added numerous other works published in Müller's Archiv and elsewhere. Important are the contributions made by Baer in anthropology (v.) and in ethnology (v.), published in Crania selecta, in Vorlesungen über Anthropologie, etc. He discovered artificially deformed skulls in ancient burials in the Crimea; he carried out various comparative craniological observations and founded the German Anthropological Society. Baer also contributed notably to the development of geographical knowledge, especially of Russia: among other things he explored the Caspian basin, studied the extremely slow phenomena of the Baltic coasts and in 1837 made a long voyage of exploration in the subarctic regions, pushing as far as Novaya Zemlya. From the observation that in the Siberian rivers flowing toward the Arctic Ocean the eastern bank is more eroded than the western one, he derived the law of the deviation of rivers as a consequence of the earth's rotation. He founded the Geographical and Ethnological Society of St. Petersburg and in 1835 began with Helmersen the publication of the Beiträge zur Kenntniss des russischen Reichs: there and in the bulletin of the Academy of Sciences of St. Petersburg he published most of his geographical works. In his last work, Studien aus dem Gebiete der Naturwissenschaften (St. Petersburg 1876), Baer clarified his philosophical position with respect to the general problems of science, vigorously combating materialist doctrines and the Haeckelian excesses of Darwinism, refuting the "biogenetic law" (v.) in support of which Haeckel had adduced Baer's observations, and upholding the finalistic conception of life with considerations drawn from embryology. The reading of the works of E. E. Fichte induced Baer, as he himself declared (Stölzle, pp. 419, 438), to modify in a theistic sense the pantheistic views to which he had previously been inclined.

Sergio Beer