Brongniart, Adolphe-Théodore

(b. Paris, France, 14 January 1801; d. Paris, 18 February 1876)

paleobotany, plant anatomy, plant taxonomy.

The son of Alexandre Brongniart, the eminent geologist, Brongniart was trained by his father and at an early age collaborated with him. He rapidly showed signs of being a superior student, and his gifts were so carefully developed that he became a precocious scientist capable of an immediately high level of work.

Nothing in Brongniart’s life indicates the slightest hesitation in his pursuit of science. Between 1817 and 1828 he was able to attend to his studies and his initiation in science while carrying on original research. In 1818 he was registered for courses in medicine, but they constituted only a fraction of his occupations; two years later he published his first report, on a new genus of crustacean. After this youthful attempt Brongniart hoped to reach the level of the great biological movements of his time: research on the primary divisions of the vegetable kingdom, anatomy and taxonomic anatomy (following the work of Mirbel and Candolle), and the theory of generalized plant sexuality. The progress already made in these fields, as well as that in geology and botanical geography (he had early acquired a knowledge of tropical flora), heralded a new science of which Brongniart was to be the architect: the comparative morphology of living and fossil plants.

In 1822 Brongniart published his first important memoir, on the classification and distribution of fossil plants. In it he conceived of paleobotany as a part of botany and gave it a theoretical value of prime importance for biology as well as for geology. Coming as he did after such scholars as Ernst Schlotheim and Kaspar von Sternberg, Brongniart was not entirely an innovator, but his study did show an assurance previously unknown.

The masterworks of 1828, the Prodrome and the Histoire des végétaux fossiles, mainly confirmed and extended his early ideas, giving them foundation and breadth of perspective. The Histoire, which he had hoped to continue in a second volume (only the first parts appeared in 1837), was a long, methodical, detailed, and precise study that clearly showed Brongniart’s two concerns: nomenclature and illustration. Its general principles and theoretical views were expressed in condensed form in the Prodrome, to striking effect. In it Brongniart recognized the existence of four successive periods of vegetation, each characterized geologically. Three were particularly well characterized: the first, extending to the end of the Carboniferous, by the vascular cryptogams; the third, covering the Jurassic and the Cretaceous, by ferns and the gymnosperms; the fourth, which was the Tertiary, by the dicotyledons.

Brongniart then divided the vegetable kingdom into six classes: Agamae (thallophytes), cellular cryptogams (liverworts and mosses, i.e., Hepaticae and Muscae), vascular cryptogams, and three classes of phanerogams: gymnosperms, monocotyledonous angiosperms, and dicotyledonous angiosperms. This excellent classification clearly indicated modern views, but unfortunately, for unknown reasons, Brongniart did not follow it in his later publications. For the first time gymnosperms were taken as a class and correctly placed among the phanerogams. After more than a century, the cotyledons were no longer the major criterion for classification.

Although Brongniart agreed with Cuvier’s theories of fixity of species and cycles in the history of the earth, he, like Candolle before him, accepted the law of organic improvement of plants, adding to it a fundamental geological dimension. The sequence went from the structural simplicity of the Carboniferous plant life, to the intermediary structure of the Jurassic gymnosperms, to the dicotyledons of the Tertiary and the modern flora. This work led to the biological chain formulated by Hofmeister in 1851. Brongniart noted both the phenomena of extinction, which affected the genera and even the classes of the Carboniferous flora, and the correspondence between changes in fauna and flora and changes in climate.

At twenty-seven, Brongniart seemed to have reached the zenith of his creative power. The year before, he had passed his agrégation in medicine and had published a valuable memoir on the fertilization of phanerogams that followed up Amici’s early research. The improvements in the microscope (notably by Amici) finally made possible the direct study of fertilization, so Brongniart decided to repeat Vaucher’s investigation (which had been attempted by Brongniart’s great-uncle, Romain Coquebert, as early as 1794): to follow the process of fertilization all the way to the fusion of the male and female germ cells. Brongniart’s text confirmed and generalized the existence of the pollen tube; he also named the embryo sac and adopted the theory of epigenesis. But, most importantly, he confusedly provided a description of two fundamental discoveries: the existence of the tetrads, which appear during male sporogenesis, and the distinction between the fertilized egg and the seed. This work led to a new understanding of classification and of the alternation of generations.

In 1824 Brongniart and a few colleagues founded the Annales des sciences naturelles. He succeeded Desfontaines as professor of botany at the Muséum d’Histoire Naturelle in 1833, and the following year he was elected a member of the Académie des Sciences.

Until 1849 Brongniart extended his researches to the whole plant world, past and present, including taxonomy, anatomy, or biology. He was one of the first, after H. T. M. Witham’s work of 1833, to use thin sections in paleobotany (inaugurated by W. Nicol). His most notable use of thin sections was in his famous anatomical observations on the Sigillaria (1839), a genus in the class of plants proper to the Primary era and related to the lycopods.

In 1849 Brongniart’s article “Végétaux fossiles” appeared in d’Orbigny’s Dictionnaire universel d’histoire naturelle and was also printed separately under the title Tableau des genres de végétaux fossiles…. This was the first attempt at a synthesis of paleobotany: the inventory of fossil genera as a whole and the place of these genera in natural classification.

After 1849 Brongniart’s activity turned more and more to the systematic study of living plants, particularly the Neo-Caledonian flora: Proteaceae, Eleocarpaceae, Saxifragaceae, Cunoniaceae, Myrtaceae, Pittosporaceae, Dilleniaceae, Umbelliferae, Epacridaceae, palms, conifers, and so on. His articles appeared in such journals as Annales des sciences naturelles, Annales du Muséum, Archives du Muséum, Comptes rendus de I’Académie des sciences, and Bulletin de la Société botanique de France. Yet he had not abandoned his interest in paleobotany. A quarter of a century after the Tableau des genres… fossiles, his pupil Grand’ Eury sent him some silicified seeds from Grand’ Croix, near St. Étienne. Brongniart went to work with enthusiasm and made a last great discovery: the pollen chamber in fossil cycads, a structure that he and Bernard Renault also found in a living cycad species from Mexico—Ceratozamia brongniart—in 1846.

Brongniart was one of the greatest French botanists of the nineteenth century, and his work exerted a major influence on the progress of botany. It is possible, however, that he was too much influenced by Cuvier and too little by Lamarck, for the theoretical aspect of his work may not quite equal its descriptive excellence.

BIBLIOGRAPHY

I. Original Works. Brongniart’s writings include “Mémoire sur le Limnadia, nouveau genre de crustacés,” in Mémoires du Muséum d’histoire naturelle, 6 (1820), 83–92; “Description d’un nouveau genre de fougére nommée Ceratopteris,” in Bulletin de la Société philomatique de Paris, 7 (1821), 184–187; “Sur la classification et la distribution des végétaux fossiles en général, et surceux des terrains de sédiment supérieur en particulier,” in Mémoires du Muséum d’histoire naturelle, 8 (1822), 203–240, 297–348, also published separately; Essai d’une classification naturelle des champignons, ou Tableau méthodique des genres rapportés jusqu’à cette famille (Paris, 1825); “Recherches sur la génération et le développement de I’embryon dans les végétaux phanérogames,” in Bulletin de la Société philomatique de Paris, 12 (1826), 170–175, and in Annales des sciences naturelles, 12 (1827), 14–53, 145–172, 225–296; “Mémoire sur la famille des Rhamnés,” ibid., 10 (1827), 320–386, his thesis for the M.D.; Prodrome d’une histoire des végétaux fossiles, (Paris, 1828); Histoire des végétaux fossiles, ou Recherches botaniques et géologiques sur les végétaux renfermés dans les diverses couches du globe, 2 vols. (Paris, 1837); Botanique du voyage de la Coquille pendant 4 années 1822–1825… (Paris, 1829), with atlas; “Recherches sur la structure et les fonctions des feuilles,” in Annales des sciences naturelles, 21 (1830), 420–458; “Observations sur la structure intérieure du Sigillaria elegans, comparée à celle des Lepidodendron et des Stigmaria, et à celle des végétaux vivants,” in Archives du Muséum d’histoire naturelle, 1 (1839), 405–460; “Note sur un nouveau genre de Cycadées du Mexique,” in Annales des sciences naturelles, 3rd ser., 5 (1846), 1–9; “Végétaux fossiles,” in d’Orbigny’s Dictionnaire universel d’histoire naturelle, XIII (Paris, 1849), 52–173, published separately as Tableau des genres de végétaux fossiles considérés sous le point de vue de leur classification botanique et de leur distribution géologique (Paris, 1849); Rapport sur les progrés de la botanique phytographique (Paris, 1868); “Études sur les graines fossiles trouvées à I’état silicifié dans le terrain houiller de Saint-Étienne,” in Annales des sciences naturelles, section botanique, 20 (1874), 234, and Comptes rendus de l’Académie des sciences, 79 (1874), 343, 427, 497; “Sur la structure de l’ovule et da la graine des Cycadées, comparée à celle de diverses graines fossiles du terrain houiller,” ibid., 81 (1875), 305–307; and Recherches sur les graines fossiles silicifiées (Paris, 1881), with a preface on Brongniart’s work by J.-B. Dumas.

II. Secondary Literature. For biographical information on Brongniart, see Maxime Cornu, “Éloge de M. Ad. Brongniart,” in Revue Scientifique, 10 (1876), 564–574; Pierre Duchartre et al., Discours prononcé le 21 fevrier 1876 sur la tombe de M. Adolphe Brongniart (Paris, 1876), with a good list of works by Brongniart; J.-B. Dumas, “Les Brongniart, généalogies et compléments biographiques” (1923–1924), MS in Bibliothèque du Muséum d’histoire naturelle, and “La famille d’un échevin de Paris: Les Hazon. Généalogies et compléments historiques” (1939), MS in Bibliothéque du Muséum d’histoire naturelle; L. de Launay, Une grande famille de savants: Les Brongniart (Paris, 1940); and G. de Saporta, “Étude sur la vie et les travaux paléontologiques d’Adolphe Brongniart,” in Bulletin de la Société botanique de France, 7th ser., 4 (1876), 373, meeting of 20 April.

Brongniart’s work is discussed in Cornu and in Saporta (above). See also P. Bertrand, “La chaire d’anatomie comparée des végétaux vivants et fossiles du Muséum,” in Bulletin du Muséum d’histoire naturelle, 2nd ser., 13 , no. 5 (1941), 369–391; K. Chester, “Fossil Plant Taxonomy,” in W. B. Turrill, ed., Vistas in Botany, IV (Oxford, 1964), 238–297; F. H. Knowlton, Fossil Wood and Lignite of the Potomac Formation, U.S. Geological Survey Bulletin no. 56 (Washington, D. C., 1889), pp. 1–72; and L. F. Ward, “Historical Review of Paleobotanical Discovery,” in U.S. Geological Survey, Fifth Annual Report (1883–1885) (Washington, D. C., 1885), pp. 368–425.

Jean-FranÇois Leroy