KÜhn, Alfred

(b. Baden-Baden, Germany, 22 April 1885; d. Tübingen, Germany, 22 Novermber 1968)

zoology.

Kühn began to study natural science in 1904 at the university of Freiburg in Breisgau, where he studied mainly with the zoologist A. Weismann and the physiologist Johannes von Kries. He received his doctorate in 1908 with a dissertation entitled Die Entwicklung der Keimzellen in den parthenogenetischen Generationen der Cladocernen Daphnia pulex De Geer und Polyphemus pediculus De Geer. In 1910 he qualified as a lecturer in zoology at the University of Freiburg, and in 1914 he was named extraordinary professor. After World War I Kühn worked for a short time under Karl Heider at the zoology laboratory of the University of Berlin. In 1920 he succeeded E. Ehlers in the chair of zoology at the University of Göttingen. he developed a zoology laboratory at Göttingen employing the most up-to-date concepts, and through his stimulating teaching and his widespread research activity he attracted a large number of students to it.

In 1937 he was appointed second director of the Kaiser Wiljelm Institute for Biology in Berlin-Dahlem, where he was able to devote himself completely to research. in 1951 the institute was moved to Tübingen—with the new name of the Max Planck Institute for biology—and until 1958n Kühn was administrative director of the much expanded organization. Kühn continued to work intensively in his old laboratory as a scientific member of the institute until his death. From 1946 to 1951 he was also professor of zoology and director of the zoology laboratory at the University of Tübingen.

From the start of his career, Kühn’s scientific work encompassed very varied fields. in Freiburg he simultaneously conducted investigations in embryology, cytology, and the physiology of sensation. these included studies on the ontogenesis and phylogenesis of the hydroids; the development of the cladocerans; processes of division among various protozoans, the physiology of the reptilian ear labyrinth, the spinal cord of the dove, and reflexes in crabs. His anleitung zu tierphysiologischen Grundversuchen appeared in 1917 and die Orientierung der Tiere im Raum in 1919. At Göttingen, Kühn also studied the Physiology of Sensation —the color vision of bees and cuttlefish.

Kühn soon concentrated his efforts almost entirely on investigation question of genetics and early development, occasionally in collaboration with Karl Henke. He examined the flour month Ephestis kühniella z, which beame the mojor object of study in genetics after Drosphila; later they were joined by the microlepidoptera Ptychopoda seriata. the oration of patterns and the effect of genes were the central problems of Kühn’s research. Applying the genetic and developmental approaches to the design patterns on butterfly wings soon led to innovative concepts in genetics. further investigations of eye color mutants resulted in the inclusion of the ommochrome pigments in the chain of biochemical processes set off by the genes. As a result in the inclusion of the ommochrome pigments in the chain of biochemical processes set o by the genes. as a result of Kühn’s collaborative work with Adolf Butenandt and his laboratory; the concept emerged that was to be the starting point for modern biochemical genetics—that genes achieve their effects by means of specific enzymes.

Kühn pursued detailed questions concerning only a few species, yet hardly anyone else could rival his grasp of the entire field of genetics and developmental physiology. His knowledge of the field is illustrated by his outstanding Vorlesungen über Entwicklungs-physiologie, which appeared in a second edition in 1965. These lectures were preceded by two textbooks—Grundriss der allgemeinen Zoologie (17th ed., 1969), and Grundriss der Vererbungslehre (4th ed., 1965). The former work, the so-called “small kühn,” is in contrast to Kühn’s contribution to the general section of the Lehrbuch der Zoologie (1932) by Claus, Grobben, and Kühn.

Kühn took a lively interest in the history of biology. He was the author of Anton Dohrn und die Zoologie siener Zeit (1950), contributed to the collection Biologie der Romantik (1948), and wrote biographies of Gregor Mendel and Karl Ernst von Baer (1957).

BIBLIOGRAPHY

I. Original Works. A bibliography of Kühn’s works is given by Viktor Schwartz in “A. Kühn 22 IV 1885–22 XI 1968,” in Zeitschrift für Naturforschung, 248 (1969), 1–4. Kühn autobiography to 1937 is in Nova Acta leopoldina, 21 (1959), 274–280.

II. Secondary Literature. See Karl Henke, in Naturwissenschaften, 42 (1955), 193–199; and A. Egelhaaf, “Aufdem Weg zur molekularen Biologie. Alfred Kühn zum Gedenken,” ibid., 56 (1969), 229–232.

Hans Querner