Joseph Dalton Hooker, an English botanist, son of Sir William Jackson Hooker, born in Glasgow in 1817. Having taken his degree in medicine, he devoted himself especially to botany. In 1839 he went as assistant surgeon on Sir James 0. Ross's antarctic expedition, and in 1847 set out on a botanical exploration to the regions of the Himalaya mountains. In 1855, having previously served as botanist in the geological survey, he became assistant to his father, whom he succeeded in 1865 as director of the Kew gardens. In 1868 he presided over the meeting of the British association for the advancement of science. In 1867 he visited Morocco, and in company with Mr. Ball ascended several of the peaks of the Atlas chain; and in 1871, also in company with Mr. Ball, ascended the Jebel Tezah, one of the summits, more than 11,000 ft. high, which no European had before ascended. In 1873 he was elected president of the royal society. His principal works are: "Flora Antarctica" (2 vols., London, 1845-'8); "Rhododendrons of the Sikkim Himalaya" (1849-'51); "Himalayan Journals" (2 vols., 1854); "Flora of New Zealand " (2 vols., 1853-'5); "Flora Tasmaniae" (1855 et seq.); and "The Student's Flora of the British Islands " (1870). He has also published, with the cooperation of George Bentham, "Genera Plantarum" (vol. i., 1867; vol. ii., part i., 1873).