BAER, KARL ERNST. — Estonian naturalist, b. at Piep in 1792, d. at Dorpat (Tartu) in 1876. Having graduated in medicine at Dorpat, in 1815 he went to Würzburg to study anatomy under Döllinger. In 1827 he was appointed professor of zoology at Königsberg and from 1829 taught for over thirty years zoology, anatomy and physiology at St. Petersburg.
Baer’s greatest studies (v.). In this science he introduced the method of direct observation and comparison, adding the embryological criterion to the anatomical-comparative one in the study of animal systematics and classification (v.). He enunciated the fundamental laws of development, developing the concept of progressive differentiation and upholding the epigenetic theory. In 1827 he discovered the mammalian ovum and described it in the Epistola de ovis mammalium et hominis genesi. He also studied the embryology of numerous invertebrates and coined the term paedogenesis for larval parthenogenesis. His principal embryological work is Untersuchungen über die Entwicklungssgeschichte der Thiere. Beobachtung und Reflexion (I, Königsberg 1827; II, 1837); to this must be added numerous other papers published in Müller’s Archiv and elsewhere. Important contributions by Baer in anthropology (v.) and ethnology (v.) appeared in Crania selecta, Vorlesungen über Anthropologie, etc. He discovered artificially deformed skulls in ancient Crimean burials; carried out various comparative craniological observations; and founded the German Anthropological Society. Baer also made notable contributions to the advancement of geographical knowledge, especially of Russia: among other things, he explored the Caspian basin, studied the bradyseismic phenomena of the Baltic coasts, and in 1837 undertook a long exploratory journey into the suburban regions, reaching Nova Zemlya. From the observation that in Siberian rivers flowing into the Arctic Ocean the eastern bank is more eroded than the western, he deduced the law of river deflection due to the Earth’s rotation. He founded the St. Petersburg Geographical and Ethnological Society and in 1835 began with Helmerson the publication of the Beiträge zur Kenntnis des russischen Reichs: in this and in the bulletin of the St. Petersburg Academy of Sciences he published most of his geographical works. In his last work, Studien aus dem Gebiete der Naturwissenschaften (St. Petersburg 1876), Baer clarified his philosophical stance on general scientific problems, vigorously opposing materialist doctrines and Haeckelian excesses in Darwinism, refuting the “biogenetic law” (v.) which Haeckel had adduced in support of his views using Baer’s own observations, and upholding a teleological conception of life based on embryological considerations. The reading of E. E. Fichte’s works led Baer, as he himself declared (Stölzle, pp. 419, 438), to modify in a theistic direction the pantheistic views to which he had previously inclined.