Dutch zoologist. Studied at Leiden, 1872–5; doctorate, 1875. Assistant, Zoötomisch Laboratorium, 1874–81. Instructor in natural history, Leiden gymnasium, 1878–88. Fisheries advisor to the government, 1888; director of the zoological station, Den Helder, 1890. First general secretary, International Council for Exploration of the Sea, 1902–8. Worked on Cirripedia; published reports on cirripedes for the Challenger Expedition and the Saboga Expedition. Discovered that organs identified by Darwin as olfactory were maxillary glands.
Sources: Biografisch woordenboek van NederlandNewman 1993 (See the bibliography for full references to sources)