(b. Jerxheim, Germany, 16 June 1858; d. Berlin, Germany, 28 April 1942)
Henking spent most of his professional career in applied fisheries research, but he also made substantial contributions to cytology and embryology in his youth. In 1878 he began studies in zoology at the University of Güttingen and completed a dissertation on the anatomy and development of the mite Thrombidium in 1882 under the direction of Ernst Ehlers. Two years later he became an assistant to his former professor and, in 1886, Privatdozent at Góttingen. He retained this post until his transfer to the German Fisheries Association in 1892.
During these years Henking published a series of papers on the general biology and development of arachnids and did extensive studies on gametogenesis, fertilization, and embryology of insects. In the course of this work he made the first observations on what were subsequently called sex chromosomes. In the maturing germ cells of the fire wasp Pyrrhocoris he noted a deeply staining chromatin body which persisted throughout most of the first meiotic division. At anaphase of the second meiotic division there was a small “chromatin element” (which Henking designated “X”) which, unlike the other chromosomes, did not appear to be double. This body went to one of the poles without dividing, lagging behind the other chromosomes, and led to the production of daughter cells with eleven and twelve chromosomes, respectively. Similar observations were subsequently made by other workers, but it was not until 1903 that the extra “chromatin element” was identified as a sex chromosome.
Henking’s work as general secretary of the Marine and Coastal Fisheries Section of the German Fisheries Association (1892–1928) dealt with scientific fisheries research and concern for the economic and social well-being of German coastal fishermen. This agency sought to build up marine fisheries so that Germany could compete equally with other European powers in exploiting marine resources.
Henking traveled abroad extensively and studied fisheries techniques which might be adapted to the German coast. His works on the culture of oysters in the United States and on the Norwegian whaling industry were the most significant. He developed statistical procedures for estimating the size of the catch of fish and directed the first statistical survey of the German North Sea fisheries, demonstrating that there had been a great rise in the population of North Sea flounder due to curtailment of intensive fishing during World War I and that the quality and size of the catch decreased substantially when intensive fishing resumed. Henking also made pioneering studies on the migration of fish and on the effect of various ecological factors, such as the nature of the seabed on the size of the catch. His studies on the Baltic salmon, sea trout, and other salmonoids provided the basis for his subsequent successful introduction of the brook trout into the Baltic area.
In terms of fishermen’s welfare, some of Henking’s more significant activities were the establishment of insurance companies for coastal fishermen, the start of vocational training programs for marine fisheries, the arrangement of government-backed loans which enabled the capital-poor coastal fishermen to acquire new motorized equipment, the development of a first-aid and rescue service for fishermen, and the establishment of societies for the betterment of the social condition of coastal fishermen.
I. Original Works. An annotated bibliography of Henking’s works to 1928 is in Otto Schubart, “Das literarische Werk von Hermann Henking,” in Zeitschrift für Fischerei, 26 (1928), 311–342. Some of Henking’s major papers are “Beiträge zur Anatomie, Entwicklungsgeschichte und Biologic von Thrombidium fuliginosum Herm.,” in Zeitschrift für wissenschaftliche Zoologie, 37 (1882), 553–663: “Unlersuehungen ueber die ersten Entwicklungsvorgänge in den Eiern der Insekten. II. Ueber Spermatogenese und deren Beziehung zur Entwickelung bei Pyrrhocoris apterus L.,” ibid., 51 (1891), 685–736; “Norwegen’s Walfang,” in Ablandungen des Deutschen Seefischereivereins, 6 (1901), 119–172: “Austernkultur und Austernfischerei in Nord-Amerika. Ergebnisse einer Studienreise nach den Vereinigten Staaten,” ibid, 10 (1907), 1–186; “Der Schollenbestand im Nordseegebiet nach Beendigung des Grossen Krieges 1914–1918, Uebersicht des Gesamtmaterials der deutschen Marktmessungen,” ibid, 13 (1922), 57–103; and “-Die Fisebwanderungen zwischen Stettiner Haaf und Ostsee.” in Zeitschrift für Fixcherei, 22 (1923). 1–92.
II. Secondary Literature. See the following (listed chronologically): O. Schubart. “Das literarische Werk von Hermann Henking,” in Zeitschrift für Fixcherei, 26 (1925), 311–342; E. Fischer, “In Memoriam, Hermann Henking,” ibid, 40 (1942). 311–342; and K. Altnoder, “Prof. Dr. Geh. Reg. Rat Hermann Henking,” in Monatshefte für Fischerei (Hamburg), n.s. 10 (1942), 93.
James D. Berger