BRONCO, usually incorrectly spelt BRONCHO (Spanish for rough), an untamed horse, especially in the United States, a mustang.
Brongniart's paper on the classification and distribution of fossil plants (1822) was followed by others bearing chiefly upon the relation between extinct and existing forms. His important "Prodrome" (contributed to the Grand Dictionnaire d'Hist. Nat., 1828, t.lvii.) brought order into chaos by a classification in which the fossil plants were arranged, with remarkably correct insight, along with their nearest living allies, and which forms the basis of all subsequent progress in this direction. It is of especial botanical interest, because, in accordance with Robert Brown's discoveries, the Cycadeae and Coniferae were placed in the new group Phanerogames gyrnnosperrnes. In this book attention was also directed to the succession of forms in the various geological periods. His great Histoire des vegetaux f ossiles, which itself was not destined to be more than a colossal fragment, was pub lished in successive parts from 1828 to 1837. His other important palaeontological contributions are his observations on the struc ture of Sigillaria (Arch. Mus. Hist. Nat. i., 1839) and his re searches on fossil seeds, of which a full account was published posthumously in 1880.
His memoir "Sur la generation et le developpement de l'em bryon des Phanerogames" (Ann. Sci. Nat. xii., 1827) is inter esting as containing the first valuable account of the develop ment of the pollen; as also a description of the structure of the pollen-grain, the confirmation of G. B. Amici's (1823) discovery of the pollen-tube, the confirmation of R. Brown's views as to the structure of the unimpregnated ovule (with the introduction of the term "sac embryonnaire"). It shows how nearly Brongniart anticipated Amici's subsequent (1846) discovery of the entrance of the pollen-tube into the micropyle, fertilizing the female cell.
His systematic work is represented by a large number of papers and monographs, many of which relate to the flora of New Cale donia; and by his Enumeration des genres de plantes cultivees au Musee d'Histoire Naturelle de Paris (1843), which is a land mark in the history of classification in that it forms the starting point of the system, modified successively by A. Braun, A. W. Eichler and A. Engler, which is now adopted in Germany. With J. V. Audouin and J. B. A. Dumas, his future brothers-in-law, he established the Annales des Sciences Naturelles in 1824; he also founded the Societe Botanique de France in 1854, and was its first president.
For accounts of his life and work see Bull. de la Soc. Geol. de France (1876), and La Nature (i876) ; the Bulletin de la Soc. Bot. de France for 1876, vol. xxiii., contains a list of his works.