Hubrecht, Ambrosius Arnold Willem

(b. Rotterdam, Netherlands, 2 March 1853; d. Utrecht, Netherlands, 21 March 1915)

Zoology, comparative embryology.

Hubrecht’s father, Paul François Hubrecht, was a banker of Dutch patrician stock; his mother, Maria Pruys van der Hoeven, came from an academic family and was a niece of the zoologist Jan van der Hoeven. Hubrecht received his training in zoology at Utrecht University under Harting and Donders, as well as in Leiden under Selenka, with whom he maintained a friendship until the latter’s death. He obtained his doctorate in 1874 under Harting. In Utrecht he moved in libertine circles and always professed to be an agnostic. Hubrecht was a man of the world, lively, amiable, and witty. He spoke and wrote three foreign languages flawlessly and was an esteemed guest at international meetings. Always generous in sharing ideas as well as scientific material with colleagues, he was an ardent believer in international scientific cooperation.

Hubrecht was for many years a member of the Dutch Royal Academy of Sciences. He was also a foreign member of both the Linnean Society of London and the Zoological Society of London. He took an active part in the founding of the Dutch Zoological Station and for many years was an editor of the leading Dutch monthly De Gids.

Hubrecht’s early interest was the invertebrates, particularly the nemerteans. His doctoral thesis (1874), which was not very significant, was based on material collected at the newly established zoological station in Naples, where he was the first Dutch guest worker and where his lifelong friendship with Anton Dohrn and Ray Lankester began. A series of more than a dozen early papers on the anatomy and development of the nemerteans (1875–1889) show Hubrecht to have been a thorough worker but still lacking the originality which characterizes his later work. That he was inclined to speculate becomes apparent from his ideas on the phylogenetic relationships between the nemerteans and the vertebrates (see the Challenger report, 1887), views which have long since been abandoned.

From 1875 until 1882 Hubrecht was curator of fishes at the Rijksmuseum voor Natuurlijke Historie in Leiden. Early in this period he worked with Gegenbaur in Heidelberg on the cranial anatomy of the Holocephali, the deep-sea ratfishes, but a product of his abiding interest in the invertebrates is his monograph on the primitive mollusk Proneomenia Sluiteri (1880). In 1878 he again spent more than six months in Naples to extend his studies on the nemerteans.

In 1882 Hubrecht succeeded Harting as professor of zoology and comparative anatomy at the University of Utrecht. During his early studies his attention had gradually shifted from adult anatomy to developmental stages. A convinced Darwinian, he was always seeking evidence for phylogenetic relationships; and he soon realized that early embryonic stages often afford more important clues than do the adult forms. Influenced, like so many of his contemporaries, by the works of F. M. Balfour, he soon came to devote all his energy to the study of comparative embryology, partly because of its interest for vertebrate evolution and partly for its own sake. It is in this field that he developed the originality and acquired the mastery that gives much of his work a lasting value, even though several of his hypotheses have since been refuted.

From about 1888 on, Hubrecht studied the early embryology and placentology of mammals. In particular he cleared up many obscure points in the development of the fetal membranes and the placenta. He began with the insectivores, which, as T. H. Huxley had suggested, occupy a central position among the mammals. In 1889 he published his first paper on mammalian embryology; it concerned the hedgehog, Erinaceus, of which he obtained specimens representing all early stages of development. In this paper he coined the term “trophoblast” for the outer cell layer of the early mammalian embryo, a term which remain in use.

Hubrecht soon found that he would also need material of certain tropical forms, including representatives of other “primitive” mammalian orders. After careful preparation he set out in 1890 on a journey lasting almost a year to the Dutch East Indies, from which he brought back an extremely valuable collection of gravid uteri of the tree shrew, Tupaia (Insectivora; now often classified with the lemuroid primates); the very rare tarsier, Tarsius, and the slow loris, Nycticebus (lemurlike animals now classified with the primates); the scaly anteater, Manis (Pholidota); and the flying lemur, Galeopithecus(Dermoptera). Through his ability to interest others in his objectives Hubrecht was able to receive material from the East Indies for many years after his return. Later he made or organized expeditions to other areas.

Two other works of this period are the memoir “Die Phylogenese des Amnions und die Bedeutung des Trophoblastes” (1895), a masterly work even though its main thesis, the phylogenetic derivation of the mammals directly from the amphibians, is no longer held, and “Early Ontogenetic Phenomena in Mammals” (1908), which contains a synthesis of his own work and that of others carried out during the two preceding decades.

Hubrecht’s brilliance of style and breadth of vision were somewhat marred by his occasional inclination to speculate too boldly and to present inferences not always firmly grounded in fact. Because of this—and because he sometimes disregarded the objections of others—he often evoked controversy. On the other hand, he bravely fought obsolete ideas and stimulated much new work. During the latter part of his life Hubrecht’s influence declined as embryologists became increasingly interested in the causal and physiological aspects of development.

In 1910 Hubrecht resigned as full professor and was appointed extraordinary professor of comparative embryology, a chair founded especially for him. In 1911 he was a founder of the Institut International d’Embryologie, an international professional society still in existence; he was its first secretary. Unfortunately, ill health increasingly prevented Hubrecht from using his leisure for the extension of his research. He died of arteriosclerosis at the age of sixty-two. The Hubrecht Laboratory (International Embryological Institute) in Utrecht, founded in his memory in 1916, still houses the Hubrecht collection.

BIBLIOGRAPHY

Among Hubrecht’s numerous writings published before 1900 are the following: Aanteekeningen over de Anatomie, Histologie en Ontwikkelingsgeschiedenis van eenige Nemertinen (Utrecht, 1874), his doctoral thesis; “Beitrag zur Kenntniss des Kopfskelettes der Holocephalen,” in Niederländisches Archiv für Zoologie, 3 (1877), 255–276; “Proneomenia Sluiteri Gen. et Sp. N. With Remarks Upon the Anatomy and Histology of the Amphineura,” ibid., supp. 2 (1880); “Contributions to the Embryology of the Nemertea,” in Quarterly Journal of Microscopical Science, n.s. 26 (1885), 417–448; “Report on the Nemertea Collected by H.M.S. Challenger During the Years 1873–76,” in C. W. Thomson and J. Murray, eds., Report on the Scientific Results of the Voyage of H.M. S. Challenger During the years 1873–76 XIX, Zoology (London, 1887); “Studies in Mammalian Embryology. I. The Placentation of Erinaceus europaeus, With Remarks on the Phylogeny of the Placenta,” in Quarterly Journal of Microscopical Science, n.s. 30 (1889), 283–404; “Studies in Mammalian Embryology. II. The Development of the Germinal Layers of Sorex vulgaris,” ibid., n.s. 31 (1890), 499–562; “Studies in Mammalian Embryology. III. The Placentation of the Shrew (Sorex vulgaris, L.),” ibid., n.s. 35 (1864), 481–538; “Spolia Nemoris,” ibid., n.s. 36 (1894), 77–126; “Die Phylogenese des Amnious und die Bedeutung des Trophoblastes,” Verhandelingen der K. Akademie van wetenschappen, 2nd sec., 4 , no. 5 (1895); “Die Keimblase von Tarsius. Ein Hilfsmittel zur schärferen Definition gewisser Säugethierordnungen,” in Festschrift zum siebenzigsten Geburtstage von Carl Gegenbaur, II (Leipzig, 1896), 147–178; The Descent of the Primates (New York, 1897); and “Ueber die Entwicklung der Placenta von Tarsius und Tupaja nebst Bemerkungen ueber deren Bedeutung als haematopoietische Organe,” in Proceedings of the Fourth International Congress of Zoology (Cambridge, 1898), app. B., pp. 343–412.

After 1900 Hubrecht published “Furchung und Keimblattbildung bei Tarsius spectrum,” Verhandelingen der K. akademie van wetenschappen, 2nd sec., 8 , no. 6 (1902); “The Gastrulation of the Vertebrates,” in Quarterly Journal of Microscopical Science, n.s. 49 (1905), 403–419; “Normentafeln zur Entwicklungsgeschichte des Koboldmaki (Tarsius spectrum) und des Plumplori (Nycticebus tardigradus),” Normentafeln zur Entwicklungsgeschichte der Wirbelthiere, no. 7 (Jena, 1907), written with F. Keibel; “Early Ontogenetic Phenomena in Mammals and Their Bearing on Our Interpretation of the Phylogeny of the Vertebrates,” Quarterly Journal of Microscopical Science, n.s. 53 (1908); and “Früheste Entwicklungsstadien und Placentation von Galeopithecus,” D. de Lange, Jr., ed., Verhandelingen der K. akademie van wetenschappen, 2nd sec., 16 , no. 6 (1919).

A secondary source is R. Assheton, “Dr. Ambrosius Arnold Willem Hubrecht,” in Proceedings of the Linnean Society of London (1915), sess. 127, 28–31.

J. Faber