WATSON, Sereno, botanist, born in East Windsor Hill, Connecticut, 1 December, 1826. He was graduated at Yale in 1847. From 1867 till 1871 he was botanist to the United States geological exploration of the 40th parallel under Clarence King. In 1874 he became curator of the herbarium of Harvard, which place he still holds. The degree of Ph. D. was conferred on him by Iowa college in 1878. He is a fellow of the American academy of arts and sciences, and of the American association for the advancement of science. Besides numerous contributions to scientific journals on American botany, he is the author of vol. v. on "Botany" in the series of "Reports of the Geological Exploration of the 40th Parallel" (Washington, 1871); " Bibliographical Index to North American Botany, Part I., Polypetalae " (1878); and, in connection with William H. Brewer and Asa Gray, " Botany of California " (2 vols., Cambridge. 1876-'80).