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.

    Hydrogéologie, in which he states that a terrestrial physics would include three subjects: meteorology, hydrogeology, and biology. He originally intended to write a work dealing with these areas but decided to postpone the sections on meteorology and biology until he had done further research.

Lamarck continued his study of meteorology in the 1780's, while he was involved in botanical studies; his awareness of the importance of climate for plants has already been mentioned. In 1797 he began publishing articles on meteorology and attempting to provide theoretical explanations for factors causing weather change. Three years later he started publishing the Annuaire météorologique. It has often been said that Lamarck wrote these volumes with the sole intention of earning money, but he showed too great an interest in them and in defending his theories for that to have been the case. It was surely no coincidence that he was assembling his meteorological studies at the same time he was elaborating his theory of evolution (the last Annuaire was published in 1810). Since climate was an important factor in his theory, it would be important to seek the laws regulating changes in climate and therefore perhaps be able to predict or understand changes in organisms more fully.

Lamarck's meteorology was devoted to a search for those laws of nature which regulate climatic change. The search was more important than the speculative theories he devised, for it indicates certain connections with the Enlightenment; he assumed that there must be simple discoverable laws governing weather changes. He also had grounds to think that such laws must exist because of Franklin's success in identifying lightning and terrestrial electricity; he greatly admired Franklin. In addition, a number of his contemporaries were studying meteorological phenomena, improving instruments, and theorizing. Lamarck was familiar with their work and used it as a point of departure for his own.

As in botany, Lamarck was attracted to the history and progressive development of meteorology. One might also say that he was concerned with a natural classification of meteorological phenomena. Finally, his theoretical considerations indicate an important thought pattern; he tried to explain all meteorological change as the result of one general cause (the moon) with irregularities produced by local circumstances.

Lamarck did have one public success with his meteorology. He recommended that the French government establish a central meteorological data bank. Following this suggestion, Chaptal established such a program in the ministry of the interior in 1800. One of Lamarck's concerns was that the daily observations from all parts of France be made in accordance with standardized procedures and instruments. The project and Lamarck's work in meteorology ended in 1810, when Napoleon ridiculed Lamarck's Annuaire.

Invertebrate Zoology and Paleontology.

When the Muséum d'Histoire Naturelle was established in 1793 and Lamarck made professor of “insects and worms,” he had the tasks of organizing the museum collection and giving courses, beginning in the spring of 1794. His only previous connection with the invertebrates was his interest in shell collecting. He was, however, a good friend of his colleague, Jean-Guillaume Bruguière, who was considered an expert on invertebrates, especially the mollusks. When Bruguière died in 1798, Lamarck finished his Histoire des vers for the Encyclopédie méthodique. Lamarck's published works in the field include a number of articles, in which he identified new genera and species and put forth some theoretical considerations, and books, the most important of which were Système des animaux sans vertèbres (1801) and his seven-volume major work, Histoire naturelle des animaux sans vertèbres (1815-1822).

Lamarck developed a system for the natural classification of invertebrates based on the anatomical findings of Cuvier. As in botany, the natural order consisted of classes arranged in a linear fashion from most complex to least complex. Such a series provided clear examples of degradation in anatomical structure and physiological function, as one system after another disappeared. Lamarck spoke of this degradation well before he advocated his theory of evolution, and that theory was first put forth as one of degradation. His study of invertebrates also helped him refine his definition of life, for the simplest organisms indicated the minimum conditions necessary for life. The origin (generation) of these simplest animals raised problems whose answer seemed to be spontaneous generation.

Burkhardt has pointed out (1972) that Lamarck came to be regarded as an expert in conchology and the successor to Bruguière. Lamarck made an important contribution to the classification of shells in his “Prodrome d'une nouvelle classification des coquilles” (1799), in which he established 126 genera. Any attempt to classify shells immediately raised the problem of what to do with fossil forms. According to Burkhardt, the pressing question of the late 1790's was whether there were any similarities between living and fossil forms. If the answer were no, the way was open to a belief in extinction, especially extinction brought about by some catastrophe. The issue being debated involved vertebrates as well. Cuvier and others were making impressive discoveries of large mammalian fossils which seemed to have no living