Victor Hensen

Christian Andreas Victor Hensen ( born February 10, 1835 in Schleswig, † April 5, 1924 in Kiel ) was a German physiologist and marine biologist. He introduced the term plankton in marine biology.

Life

Victor Hensen was born in 1835 as son of Hans Hensen ( 1787-1846 ), director of the Deaf and Dumb Institution in Schleswig. His maternal grandfather was the doctor Carl Ferdinand Suadicani. Hensen studied medicine in Würzburg, Berlin and Kiel, among others, Albert von Kölliker, Rudolf Virchow and John Peter Müller. After receiving his doctorate in 1859, he taught first as prosector and from 1864 to 1911 as Full Professor of Physiology at the Christian- Albrechts- University of Kiel. 1877/78, 1887 /88 and 1888/89 he was rector of the CAU.

His research focused on the anatomy and physiology of the sense organs. He was also known as the inventor of a method for the preparation of chemically pure glycogen from animal tissue. In his later years his main interest was in marine biology. He led several expeditions in the Atlantic, including 1889 Plankton Expedition of the Humboldt Foundation. He enriched the plankton research to quantitative statistical methods. With specially developed by him fine mesh silk nets him to filter plankton from a 200 meter high water column of 0.1 square meters. By taking samples in many parts of the ocean Hensen could estimate the total volume of plankton in the upper 200 m thick water layer. He therefore considered the "father of quantitative plankton ecology". Hensen's novel approach and its derived conclusions were hotly debated among experts. As a prominent critic Ernst Haeckel came into existence.

" Besides, " Hensen studied in the garden of his Kiel Institute the biology of earthworms. In 1871 he held in Rostock on this topic a presentation during the meeting of the Society of German Natural Scientists and Physicians "On the relations of the earthworm to the cultivation of the soil". In it, he reported, inter alia, that the earthworms far pierce the ground about one meter depth and their burrows can serve the plant roots as meridians. With his publications on the usefulness of earthworms he acquired in circles of agriculture high recognition; also Charles Darwin quoted Hensen in his last publication The Formation of Vegetable Mould through the Action of Worms repeatedly. Hensen also motivated the agricultural scientist Ewald Wollny, who initially held earthworms for pests and sought to refute Hensen's views to its basic experiments on the " earthworm " question, in which he confirmed that earthworms can cause significant yield improvements in various crops.

By the end of his life Hensen was chairman of the Prussian Commission for Scientific Exploration of the German seas. In 1975, the research vessel Victor Hensen was named after him.

Works (selection)

• Concerning the exploitation of the German coasts, Wiegandt, Hempel and Parey, Berlin 1874
• Results of Plankton Expedition of the Humboldt Foundation, 5 vols (52 deliveries ), Lipsius and Tischer, Kiel and Leipzig, 1992-1912 (Editor)