De Jussieu, a French family of natural philosophers who have been styled the " botanical dynasty " of France. The most celebrated are the following. I. Antoine, born in Lyons, July 8, 1686, died in Paris, April 22,1758. He took the degree of M. D. at Montpellier, and went to Paris in 1708, where he commenced practice, was appointed professor of botany at the jardin du roi, entered the academy of sciences in 1711, and contributed several papers to its Memoires, the most curious of which is perhaps his Re-cherches physiques sur les petrifications qui se trouvent en France de diverses parties de plantes et d'animaux Strangers. In the course of a journey through southern France and Spain he made a valuable collection of plants previously very imperfectly known. Among his published essays is a Discours sur les progres de la oota-nique (Paris, 1718). He edited Barretter's posthumous work on the plants of France, Spain, and Italy, and published a new edition of Tour-nefort's Institutiones Rei Herbarice, with an appendix (Lyons, 1719). His Traite des vertus des plantes, a synopsis of his lectures at the faculty of medicine, was published in 1772. II. Bernard, brother of the preceding, born in Lyons, Aug. 17, 1699, died in Paris, Nov. 6, 1777. In 1722 he was appointed assistant demonstrator of botany at the jardin du roi.

A man of contemplative disposition, abstemious habits, and no ambition, he never rose above this subordinate office, but gradually obtained the reputation of one of the first botanists in Europe. In 1725 he edited Tonrnefort's His-toire des plantes des environs de Paris, with additions and annotations, which were considered so valuable that he was made a member of the academy of sciences, although he was only 26 years of age. To its Memoires he contributed very few papers, and these on subjects of secondary importance, but remarkable for precision, ingenuity, and thorough method. He devised a system of classification based upon the natural affinities of plants, and applied it in 1759 to the arrangement of a botanical garden at Trianon, which had been ordered by Louis XV. His catalogue has been regarded as the foundation of the " natural system," afterward expounded by his nephew Antoine Laurent. Linnaeus entertained the highest opinion of his acquirements. III. Antoine Laurent, nephew of the preceding, born in Lyons, April 12, 1748, died in Paris, Sept. 17, 1836. He was called to the metropolis in 1765 by his uncle Bernard, and studied medicine, but ultimately devoted himself to botany.

As early as 1773 he presented to the academy of sciences a Memoire sur les renonculacees, in which the first principles of the " natural system " are clearly perceptible; and the next year he reduced the system to practice in the replanting of the botanical division in the jardin du roi. In 1778 he commenced the publication of his great work, Genera Plantarum secundum Ordines Naturales disposita, juxta Methodum in Horto Regio Parisiensi exaratum, anno 1774, which was not completed till 1789. To bring together all those plants which are allied in all essential points of structure, and to take into account the true affinities of plants on a comparison of all their organs, is the leading feature of the " Jussieuan system," which has finally superseded the artificial or sexual system of Linnaeus. In 1790 he was elected a member of the municipal council of Paris, and intrusted with the supervision of the hospitals and charities, which office he held for two years. In 1793, when the jardin du roi was reorganized as the museum of natural history, he was raised to a professorship, and while director of that institution he laid the foundation of its library, which is one of the best, if not actually the best of its kind in Europe. In 1804 he was appointed professor of materia medica at the faculty of medicine, and life member of the council of the university, but was deprived of both these offices after the restoration.

In 1826 his failing health and partial blindness caused him to resign his chair of botany in favor of his son Adrien. From 1804 to 1820 he published in the Annales du Museum a series of valuable papers prepared with reference to a new edition of his Genera Plantarum. Besides the works above mentioned, he wrote several historical notices of the museum of natural history, and a number of valuable articles on botany in the Dictionnaire des sciences naturelles, among which the one upon the "Natural Method of Plants" deserves special notice. IV. Adrien, son of the preceding, born in Paris, Dec. 23, 1797, died June 29, 1853. On taking his degree of M. D. in 1824, he defended a thesis De Eu-phorbiacearum Generibus. He succeeded his father as professor at the museum in 1826, and soon achieved a distinguished rank among botanists by his lectures and publications. In 1831 he was elected to the academy of sciences, and in 1845 was appointed to the chair of the organography of plants at the Sorbonne; his lectures there, which he continued till his death, were both brilliant and attractive.

His most important work is a Cours elementaire d'his-toire naturelle: Partie botanique (Paris, 1848; translated by I. H. Wilson, "Elements of Botany," London, 1849), which is a most valuable elementary treatise on botany. His treatise on botanical taxonomy, in the Dictionnaire uni-tersel d' histoire naturelle (1848), is also very valuable. Among his papers printed either in the Annales du Museum or the Comptes rendus de l'academie des sciences, one of the best is his Monographic des malpighiacees (1843). A very interesting essay, De la methode naturelle et des Jussieu, was published by P. Flourens in his Eloges historiques, second series. V. Laurent Pierre, cousin of the preceding, born in the department of Isere, Feb. 7, 1792. He was a member of the chamber of deputies from 1839 to 1842, and became known by educational and other popular works, including Simon de Nan-tua, ou le marchand forain (1818), which has been translated into many languages and passed through upward of 30 editions; that of 1860 contained also his CEuvres posthumes de Simon de Nantua, for which he received the Montyon prize, and similar honors were accorded by various institutions to the former and other works.

New editions of his Les petits livres du Pere Lami (6 vols.) appeared in 1853, and of his Fables et contes en vers in 1864. - His brother Alexis, a political writer and functionary, born in 1802, died in 1866.