Pierre Joseph Van Beneden was born 19 December, 1809, at Malines, Belgium, and died 8 January, 1894, at Louvain. He graduated in medicine (1831) and became Curator of the Natural History Museum, Louvain, where he became Professor of Zoology and Comparative Anatomy in 1836. Besides doing zoological work of high value which he pursued actively to the end of his life, he established at his own expense in 1843, a marine aquarium, one of the first of its kind. In parasitology he attained great distinction through his investigations upon the biology of parasitic worms and their relation to their hosts, his work Mémoire sur les vers intestinaux (viii + 376 pp. 28 pis. 4°), published in 1858, bringing him the “grand prix des Sciences physiques” of the Institut de France. In 1875 he published his results in popular form under the title Les commensaux et les parasites dans le régne animal, as one of the International Science Series, this appearing both in English and German translations. His publications number over 200 and he was joint author with Paul Gervais of a general work on medical zoology in two volumes (1859).