ETIENNE GEOFFROY SAINT-HILAIRE, (1772-1844), a celebrated French naturalist, was the son of Jean Gerard Geoffroy, procurator and magistrate of ittampes, Seine-et-Oise, where he was born, April 15, 1772. His early education was carefully superintended by his mother and paternal grandmother, and when still a boy he had already become acquainted with the masterpieces of the literature of the ancients, and of the age of Louis XIV. Destined by his friends for the church, he entered, as an exhibitioner, the college of Navarre, in Paris, where he studied natural philosophy under Brisson; and in 1788 he obtained one of the canonicates of the chapter of Sainte Croix at Etampes, and also a benefice. Science, however, offered to him a career more congenial to his tastes than that of an ecclesiastic, and, after some persuasion, he gained from his father permission to remain in Paris, and to attend the lectures at the College de France and the Jardin des Plantes, on the condition that he should likewise read law. He accordingly took up his residence at Cardinal Lemoine's college, and there became the pupil and soon the esteemed associate of Brisson's friend, Haiiy, the eminent mineral-ogist, under whose guiding influence his passion for the natural sciences daily deepened. Having, before the close of the year 1790, taken the degree of bachelor in law, he became a student of medicine, but the lectures of Fourcroy at the Jardin des Plantes, and of Daubenton at the College de France, and his favourite scientific pursuits gradually came to occupy his almost exclusive attention. His studies at Paris were at length suddenly interrupted, for, on the 12th or 13th of August 1792, Haiiy and the other profes-sors of Lemoine's college, as also 'those of the college of Navarre, were arrested by the revolutionists as priests, and confined in the prison of St Firmin. Through Daubenton and other persons of distinction with whom he was acquainted, Geoffroy on the 14th August obtained an order for the release of Haiiy in the name of the Academy; still the other professors of the two colleges, save Lhomond, who had been rescued by his pupil Tallien, remained in I confinement. Geoffroy, foreseeing their certain destruction if they remained in the hands of the revolutionists, deter-mined if possible to secure their liberty by stratagem. By bribing one of the officials at St Firmin, and disguising himself as a commissioner of prisons, he gained admission to his friends, and entreated them to effect their escape by following him. All, however, dreading lest their deliver-ance should render the doom of their fellow-captives the more certain, refused the offer, and one priest only, who was unknown to Geoffroy, left the prison. Already on the night of the 2d of September the massacre of the pro-scribed had begun, when Geoffroy, yet intent on saving the life of his friends and teachers, repaired to St Firmin. At 4 o'clock on the morning of the 3d Sept., after 8 hours' waiting, he by means of a ladder assisted the escape of twelve ecclesiastics, not of the number of his acquaintance, and then the approach of dawn and the discharge of a gun directed at him warned him, his chief purpose unaccom-plished, to return to his lodgings. Leaving Paris he retired to Étampes, where, in consequence of the anxieties of which he had lately been the prey, and the horrors which he had witnessed, he was for some time seriously ill. At the beginning of the winter of 1792 he returned to his studies in Paris, and in March of the following year Daubenton, through the interest of Bernardin de Saint Pierre, procured him the office of sub-keeper and assistant demonstrator of the cabinet of natural history, vacant by the resignation of Lacépède. By a law passed June 10th, 1793, Geoffroy was appointed one of the twelve professors of the newly constituted museum of natural history, being assigned the chair of zoology. In the same year he busied himself with the formation of a,menagerie at that institution. On the 6th May 1794 commenced his opening course of lectures, and on December 1st he read to the society of natural history his first paper, on the subject of the Aye-aye. It was in 1794, also, that through the introduction of Tessier he entered into correspondence with Georges Cuvier, to whom, after the perusal of some of his manuscripts, he wrote : " Venez jouer parmi nous le rôle de Linné, d'un autre législateur de l'histoire naturelle." Shortly after theappoint-ment of Cuvier as Mertrud's assistant (see vol. vi. p. 740), Geoffroy received him into his house. The two friends wrote together five memoirs on natural history, one of which, on the classification of mammals, puts forward the idea of the subordination of characters upon which Cuvier based his zoological system. It was in a paper entitled " Histoire des Makis, ou singes de Madagascar," written in 1795, that Geoffroy first gave expression to his views on " the unity of organic composition," the influence of which is percep-tible in all his subsequent writings : nature, he observes, presents us with only one plan of construction, the same in principle, but varied in its accessory parts.
In 1798 Geoffroy was chosen a member of the great scientific expedition to Egypt. With Delile and Larrey, on the capitulation of Alexandria in August 1801, he re-sisted the claim made by the British general Hutchinson to the collections of the expedition, sending him word that, were his demand persisted in, history would have to record of him that he also had burnt a library in Alexandria. Early in January 1802 Geoffroy returned to his accustomed labours in Paris. He was elected a member of the academy of sciences of that city in September 1807. In March of the following year the emperor, who had already recognized his national services by the award of the cross of the legion of honour, selected him to visit the museums of Portugal, for the purpose of procuring from them collections, and these, though in the face of considerable opposition from the British, he eventually was successful in retaining as a permanent possession for his country. In 1809, the year after his return to France, he was made professor of zoology of the faculty of sciences at Paris, and from that -period he devoted himself more exclusively than before to the study of anatomical philosophy. In 1815 he was elected political representative for his native town. Three years later he gave to the world the first part of his celebrated Philosophie Anatomique,th.e second volume of which, published in 1822, and memoirs subsequently written account for the forma-tion of monstrosities on the principle of arrest of develop-ment, and of the attraction of similar parts. When, in 1830, Geoffroy proceeded to apply to the invertebrata his views as to the unity of animal composition, he found a vigorous opponent in Georges Cuvier, and the discussion between them, continued up to the time of the death of the latter, soon attracted the attention of the -scientific throughout Europe. Geoffroy, a synthesist, contended, in accordance with his theory of unity of plan in organic com-position, that all animals are formed of the same elements, in the same number, and with the same connexions : homo-logous parts, however they differ in form and size, must remain associated in the same invariable order. With Goethe he held that there is in nature a law of compensation or balancing of growth, so that if one organ take on an excess of development, it is at the expense of some other part (cf. Darwin, Origin of Spiecies, 5th ed., p. 182) ; and he maintained that, since nature takes no sudden leaps, even organs which are superfluous in any given species, if they have played an important part in other species of the same family, are retained as rudiments, which testify to the per-manence of the general plan of creation. It was his con-viction that, owing to the conditions of life, the same forms had not been perpetuated since the origin of all things, although it was not his belief that existing species are becoming modified (see Darwin, op. cit., p. xvi.). Cuvier, who was an analytical observer of facts, admitted only the prevalence of "laws of coexistence" or "harmony" in animal organs, and maintained the absolute invariability of species, which he declared had been created with a regard to the circumstances in which they were placed, each organ contrived with a view to the function it [had to fulfil, thus putting, in Geoffrey's consideration, the effect for the cause. In July 1840 Geoffroy became blind, and some months later he had a paralytic attack. From that time his strength gradually failed him. He resigned his chair at the museum in 1841, and on the 19th June 1844, at the age of 72, he died.
Geoffroy wrote Catalogue des Mammifères du Muséum national d'Histoire naturelle, 1813, not quite completed; Philosophie anato-mique,t. i., Des organes respiratoires, 1818, & t. ii., Des Monstruo-sités humaines, 1822 ; Système dentaire des Mammifères et des Oiseaux, lstpt., 1824; Sur le Principe de l'Unité de Composition organique, 1828 ; Cours de l'Histoire naturelle des Mammifères, 1829; Principes de Philosophie zoologique, 1830; Etudes progressives d'un Naturaliste, 1835; Fragments biographiques, 1832; Notions synthétiques, historiques, et physiologiques de Philosophie naturelle, 1838 ; and other works ; also part of the Description de l'Egypte par la Commission des Sciences, 1821-30; and, with F. Cuvier, Histoire naturelle des Mammifères, 4 vols., 1820-42; besides very numerous papers published in the Annales du Muséum, the Ann. des Soi. not., the Bulletin philomatique, La Décade égyptienne, La Décade philosophique, the Bev. encyclopédique, Mém. de l'Acad. des Sciences, and elsewhere, among the subjects of which are the anatomy of marsupials, ruminants, and electrical fishes, the vertebrate theory of the skull, the opercula of fishes, teratology, palaeontology, and the influence of surrounding conditions in modifying animal forms.
See Vie, Travaux, et Doctrine Scientifique d'Etienne Geoffroy Saint-ÏJilaire, par son fils M. Isidore Geoffroy Saint-Eilaire, Paris and Strasburg, 1847, to which is appended a list of Geoffroy's works; and Joly, in Siog. Universelle, t. xvi., 1856. (F. H. B.)