Mary Lyon, an American teacher, born in Buckland, Mass., Feb. 28, 1797, died in South Hadley, Mass., March 5, 1849. Under great difficulties she acquired by persevering effort such an education as she judged necessary to qualify her as a teacher, and for several years was engaged in teaching in different schools. In 1837 she succeeded in opening at South Hadley, Mass., the Mount Holyoke female seminary, upon a plan which she had been maturing for many years, the peculiar feature of which was the combination of domestic labor with the highest moral and intellectual culture. She presided over this institution with great success until her death; and many of her pupils have since established schools upon a similar plan. Her only published works are a pamphlet entitled "Tendencies of the Principles embraced and the System adopted in the Mount Holyoke Female Seminary " (1840), and " The Missionary Offering" (Boston, 1843). - See "Power of Christian Benevolence, illustrated in the Life and Labors of Mary Lyon," by Edward Hitchcock, D. D. (Northampton, 1851; 2d ed., 1860).