GEOFFROY 

SAINT-HILAIRE, ISIDORE (r8o5-1861), French zoologist, son of the preceding, was born at Paris on the 16th of December 1805 . In his earlier years he showed an aptitude for mathematics, but eventually he devoted himself to the study of natural history and of medicine, and in 1824 he was appointed assistant naturalist to his father . On the occasion of his taking the degree of doctor of medicine in September 1829, he read a thesis entitled Propositions sur la monstruosite, consideree chez l'homme et les animaux; and in 1832-1837 was published his great teratological work, Histoire generale et particuliere des anomalies de ?organisation chez l'homme et les animaux, 3 vols . 8vo. with 20 plates . In 1829 he delivered for his father the second part of a course of lectures on ornithology, and during the three following years he taught zoology at the Athenee, and teratology at the Ecole pratique . He was elected a member of the academy of sciences at Paris in 1833, was in 1837 appointed to act as deputy for his father at the faculty of sciences in Paris, and in the following year was sent to Bordeaux to organize a similar faculty there . He became successively inspector of the academy of Paris (1840), professor of the museum on the retirement of his father (1841), Inspector-general of the university (1844), a member of the royal council for public instruction (1845), and on the death of H . M . D. de Blainville, professor of zoology at the faculty of sciences (1850) . In 1854 he founded the Acclimatization Society of Paris, of which he was president . He died at Paris on the loth of November 1861 . Besides the above-mentioned works, he wrote: Essais de zoologie generale (1841); Vie .

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Etienne Geoff roy Saint-Hilaire (1847); Acclimatalion et domestication des animaux utiles (1849; 4th ed., 1861); Letires sur les substances alimentaires et particulierement sur la viande de cheval (1856) ; and Histoire naturelle generale des regnes organiques (3 vols., 1854-1862), which was not quite completed . He was the author also of various papers on zoology, comparative anatomy and palaeontology . the figure of the earth and the varieties of crustal relief . Hence mathematical geography (see MAP), including cartography as a practical application, comes first . It merges into physical geography, which takes account of the forms of the lithosphere (geomorphology), and also of the distribution of the hydrosphere and the rearrangements resulting from the workings of solar energy throughout the hydrosphere and atmosphere (oceanography and climatology) . Next follows the distribution of plants and animals (biogeography), and finally the distribution of mankind and the various artificial boundaries and redistributions (anthropogeography) . The applications of anthropogeography to human uses give rise to political and commercial geography, in the elucidation of which all the earlier departments or stages have to be considered, together with historical and other purely human conditions . The evolutionary idea has revolutionized and unified geography as it did biology, breaking down the old hard-and-fast partitions between the various departments, and substituting the study of the nature and influence of actual terrestrial environments for the earlier motive, the discovery and exploration of new lands .