GEOFFROY SAINT-HILAIRE, ISIDORE, a French and naturalist, son of Etienne Geoffroy, was b. in Paris in 1805, and died in that city in 1861. Educated in natural history by his father, he became assistant naturalist at the museum when only 19 years of age, and in 1830 lie delivered the zoological lectures in that institution as his father's substitute. The science of teratology (q.v.), or of the laws which regulate the development of monstrosities, which had occupied much of his father's attention. was taken up with great zeal by the son, and in 1832 he published the first volume of his Ilistaire Generale et ParticuliCre des Anomalies de l' Organisation chez l' Hamitic et les Animaux, ou Traite de Teratologie, the third and concluding volume of which did not appear till 1837. This work is of extreme value, and will always serve as the starting point for those who may occupy themselves with this important branch of biological investigation. Having for a long time the superintendence of the menagerie of the
museum, he was led to study the domestication of foreign animals in France; and the results of these investigations may be found in his Domestication et Naturalisation des Animaux Utiles (1854), and the Socifte pour Acclimataticp des Animaux Utiles, of which he was the founder; In 1852, he ,published.the first volume of a great work entitled, Ilistoire Generale des Regnes Organiques, in which he intended to develop the doctrines handed down to him by his father, but which is left in an unfinished state by his premature death. He was a strong advocate of the use of horse-flesh as human food, and published his Lettres sur les Substances Alimentaires, et particularement sur la Viande de Cheval (1850), with the view of bringing his views on the subject before the general public.