LAMARCK, JEAN BAPTISTE PIERRE ANTOINE DE MONET DE (b. Bazentin-le-Petit, Picardy, France, 1 August 1744; d. Paris, France, 28 December 1829), botany, invertebrate zoology and paleontology, evolution.

    with the most primitive level and working up through time to the more complex. Lamarck shared with the Philosophes a belief in the idea of progress in human knowledge, which is clearly seen in his brief history of botany. Increasing progress over time is almost inevitable if circumstances are favorable. He was later to apply such a conception to natural as well as human history.

In the Dictionnaire de botanique Lamarck developed the theoretical and philosophical ideas he had advanced in the Flore. The “Discours préliminaire” was an expanded version of the history of botany from the Flore and it showed even more fully Lamarck's belief in the idea of progress. Lamarck himself had made some progress in his search for a natural method of vegetable classification. Following some suggestions from A. L. de Jussieu, he decided that a hierarchical arrangement could be established only for the larger groupings or classes of plants. A focus on classes rather than genera or species would later be an important part of his evolutionary theory. Lamarck's new views were set forth in the article “Classe,” in which he listed the classes of plants, arranged from the most complex to the least complex; placement on the scale was determined by relative structural complexity. To complete the realm of living organisms, Lamarck presented a parallel series of descending classes for the animal kingdom. In pointing out the similarities between plants and animals, he laid the foundations for his biology. In another table the nonliving natural productions were also arranged in order of decreasing complexity. Lamarck held that all mineral substances were produced by organic beings as they and their waste products decayed over time and their debris underwent successive transformations until the simple element level was reached. The fact that Lamarck drew up these tables of comparison shows his concern with seeing nature as a whole.

During the 1790's, Lamarck's interests and studies turned away from botany to new fields. After 1800, when he began advocating his theory of evolution, he wrote only one work specifically dealing with botany. His two-volume Introduction à la botanique (1803) formed part of the fifteen-volume Histoire naturelle des végétaux; the rest of the work was written by Mirbel. This study of the vegetable kingdom was in turn part of the larger eighty-volume Cours complet d'histoire naturelle pour faire suite à Buffon edited by Castel. Lamarck's Introduction was his only botanical work to include his evolutionary theory. He stressed that for the vegetable kingdom a natural order of classification beginning with the simplest class and ending with the most complex class reflected the order which nature had followed in producing these groups in time. Although this was his last botanical work, Lamarck did not stop thinking about the vegetable kingdom. He discussed it in all of his evolutionary works and drew a number of examples from it.

Institutional Affiliations.

Lamarck's election to the Académie des Sciences as an adjoint botanist was engineered by Buffon in 1779. He was promoted to an associate botanist in 1783 and became a pensioner in 1790. The Academy was suppressed in 1793, during the Terror; it was reorganized two years later as part of the Institut National des Sciences et des Arts. From 1795 until his death, Lamarck was a resident member of the botanical section. Until his health failed, he attended meetings regularly and prepared a number of reports on works submitted to the Academy.

In the 1790's Lamarck took an active role in the newly formed Société d'Histoire Naturelle, which included the prominent French naturalists of the time. He helped edit several of its publications and contributed a number of articles on botany and invertebrates to them.

Lamarck's most significant institutional affiliation was with the Jardin du Roi, which had become an important scientific center in the second half of the eighteenth century under the leadership of Buffon. From 1788 until 1793, Lamarck held various minor botanical positions there. During the French revolution, when all the institutions of the ancien régime were being subjected to critical examination, suggestions were made for the reorganization of the Jardin du Roi, among them a memoir by Lamarck. In 1793, when the academies were suppressed as privileged institutions of the old order, the Jardin du Roi was transformed into the Muséum National d'Histoire Naturelle. The botanical positions were filled by others and Lamarck was made a professor of zoology for the study of “insects and worms,” a group of animals which he renamed “invertebrates.” While this represented a rather drastic shift in fields for him, Lamarck was not unhappy about it, for he had been developing an interest in these animals. His new duties consisted of giving courses and classifying the large collection of invertebrates at the museum. He also took an active part in the administration of the new institution. Lamarck's own work benefited from contacts with his colleagues and their scientific investigations at the museum.

Chemistry.

The first long works that Lamarck published after the reorganization of the museum dealt not with invertebrates but with chemistry, a subject in which he had been interested for many years. He had begun to study chemistry in the 1770's, when