Robert Brown

Brown, Robert (1773–1858), Scottish physician and botanist. Brown discovered the natural continuous random movement of microscopic particles now known as Brownian motion (1827), and identified the nucleus as a constituent of nearly all living plant cells (1831). Brown studied and collected specimens of flora in Australia and Tasmania. He identified the two plant groupings of gymnosperms (conifers) and angiosperms (flowering plants), and otherwise elaborated the system of plant classification. He was also a pioneer in the microscopic examination of plant fossils.

See also: Botany.