(b. Kirwein, Moravia, Austria, 3 April 1854; d. Vienna, Austria, 18 January 1941)
Hatschek, who came from an affluent family, studied zoology in Vienna under Claus and in Leipzig under Leuckart. He gained his doctorate in Leipzig in 1876 with the dissertation “Beiträge zur Entwicklungsgeschichte der Lepidopteren” (1877). He was greatly influenced by Haeckel, with whom he had close ties from 1876 until Haeckel’s death in 1919 (Georg Uschmann, Geschichte der Zoologie und der zoologischen Anstalten in Jena 1779–1919 [Jena, 1959], pp. 133–135).
After acquiring his Ph.D., Hatschek worked in Vienna, where he qualified as a university lecturer in 1884. Upon the recommendation of Haeckel he was appointed as ordinary professor at the Zoological Teaching Council of the German University in Prague, and from 1896 to 1925 he headed the Zoological Institute of the University of Vienna.
Hatschek married Marie Rosenthal, a portrait painter, in 1898. He repeatedly fell into periods of nervous depression which hindered the continuity of his scientific work. From time to time he occupied himself with writing short stories or with inventions, which led him to study ornithopters. He was a member of the Austrian Academy of Sciences and of the Leopoldine German Academy.
Hatschek’s scientific works were influenced by the development of contemporary zoology. Questions on the development and systematic placing of animals were being investigated in the light of Darwinian theory. Within this framework he was led to investigate the growth and metamorphosis of the larva of the annelids (or trochophores) and to formulate the so-called trochophore theory (1877–1891). According to this hypothesis, the trochophore stage is typical not only for the annelids but also for the mollusks, so that a relational connection can be established between the two morphologically different animal groups (“trochophore animals”).
Hatschek further came to the conclusion that the trochophores, as a transitory phase of development for the annelids and mollusks, corresponded to a permanent state in the rotifers. He saw these forms as the ancestral stock of the classification he named “Zygoneura.” Haeckel’s influence was evident in Hatschek’s indication of the possibility of tracing back the Zygoneura to the trochophore stage and that this larva probably repeated an ancestral stage.
Hatschek later investigated the development of mesoderms in the ctenophorans, presenting a new system. He arranged the Metazoa in three main branches: Coelenterata, Ecterocoelia (or Zygoneura), and Enterocoelia (apropos of this see his Das neue zoologische System [Leipzig, 1911]). Hatschek’s studies on the amphioxus (Branchiostoma lanceolatum), which he began in 1881, led to important information on the development and stratification of this animal.
He also busied himself with the larva of the petromyzons (or ammocoetes). Out of these researches arose his “Studien zur Segmenttheorie des Wirbeltierkopfes” (1906, 1909, 1929). Along with a succession of smaller works, Hatschek published a textbook, Lehrbuch der Zoologie (1888–1891), which, like his Elementarkurs der Zootomie (1896), was never completed.
I. Original Works. “Studien über Entwicklungsgeschichte der Anneliden,” in Arbeiten aus dem Zoologischen Institute der Universität Wien, 1 (1878); “Studien über die Entwicklung des Amphioxus,” ibid., 4 (1882); “Über den Schichtenbau von Amphioxus,” in Anatomischer Anzeiger, 3 (1888); Lehrbuch der Zoologie, eine morphologische Übersicht des Tierreiches zur Einführug in das Studium der Wissenschaft, pts. 1–3 (Jena, 1888–1891); “Die Metamerie des Amphioxus und des Ammocoetes,” in Verhandlungen der Anatomischen Gesellschaft, 6 (1892).
See also “Studien zur Segmenttheorie des Wirbeltierkopfes”: I. “Das Acromerit des Amphioxus,” in Morphologisches Jahrbuch, 35 (1906); II. “Das primitive Vorderende des Wirbeltierembryos,” ibid., 39 (1909); III. “Über das Acromerit und über echte Ursegmente bei Petromyzon,” ibid., 40 (1909); and “Über die Mesodermsegmente der zwei Kopfregionen bei Petromyzon fluviatilis,” in Morphologisches Jahrbuch, 61 (1929); Das neue zoologische System (Leipzig, 1911).
II. Secondary Literature. Paul Krüger, “Berthold Hatschek zum 80. Geburtstage,” in Forschungen und Fortschritte, 10 (1934), 120; “Glückwunschadresse der Akademie der Wissenschaften in Wien,” in Almanach für das Jahr 1934 (1935), pp. 257–259; Otto Storch, “Berthold Hatschek,” in Österreichische Akademie der Wissensehaften, Almanach für das Jahr 1949 (1950), pp. 284–296; Wilhelm Marinelli, “Berthold Hatschek,” in Österreichische Naturforscher und Techniker (Vienna, 1950), pp. 90–93; Helmut Dolezal, “Hatschek, Berthold,” in Neue Deutsche Biographie, VIII (1969), 56–57.