DECAISNE, JOSEPH. - Botanist, born in Brussels on 7 March 1807, died in Paris on 8 February 1882. Having begun at the Jardin des plantes, he rose to become director of cultivation at the museum and president of the Botanical Society. Of an eminently inductive mind, he sought to test the Darwinian hypothesis through observation and experiment in order to “catch in the act” the “struggle for existence” among species of the genus Pirus, without managing to confirm that hypothesis.
BIBL.: Principal work: Le Jardin fruitier du Muséum ou Iconographie de toutes les espèces et variétés d'arbres fruitiers cultivés dans cet établissement, 9 vols., Paris 1858–75. Biographical data: M. Berthelot, Science et éducation, Paris 1901, pp. 177–209. A list of D.’s publications is found in the Catalogue général de la bibliothèque Nationale de Paris, XXXVI, pp. 675–81.